Methods, devices, and systems for non-invasive delivery of microwave therapy

ABSTRACT

Methods, apparatuses and systems are provided for non-invasive delivery of microwave therapy. Microwave energy may be applied to epidermal, dermal and subdermal tissue of a patient to achieve various therapeutic and/or aesthetic results. In one embodiment, the microwave energy is applied to a target tissue via an energy delivery applicator connected to an energy generator. The energy delivery applicator may comprise one or more antennas, including monopole, dipole, slot and/or waveguide antennas (among others) that are used to direct the microwave energy to the target tissue. The energy delivery applicator may also comprise a cooling element for avoiding thermal destruction to non-target tissue and/or a suction device to localize thermal treatment at specific portions of a skin fold.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.15/288,949, filed Oct. 7, 2016, now U.S. Pat. No. 10,463,429, which is acontinuation of U.S. application Ser. No. 12/450,860, filed Oct. 16,2009, now abandoned, which is a national phase application under 35 USC371 of PCT/US2008/060929, filed Apr. 18, 2008, which application claimspriority under 35 USC 119(e) to U.S. Provisional Patent Application No.60/912,899, entitled “Methods and Apparatus for Reducing SweatProduction,” filed Apr. 19, 2007, U.S. Provisional Patent ApplicationNo. 61/013,274, entitled “Methods, Delivery and Systems for Non-InvasiveDelivery of Microwave Therapy,” filed Dec. 12, 2007, and U.S.Provisional Patent Application No. 61/045,937, entitled “Systems andMethods for Creating an Effect Using Microwave Energy in SpecifiedTissue,” filed Apr. 17, 2008. The entire disclosures of all of thepriority applications are hereby expressly incorporated by reference intheir entireties.

BACKGROUND Field of the Invention

The present application relates to methods, apparatuses and systems fornon-invasive delivery of microwave therapy. In particular, the presentapplication relates to methods, apparatuses and systems fornon-invasively delivering microwave energy to the epidermal, dermal andsubdermal tissue of a patient to achieve various therapeutic and/oraesthetic results.

Description of the Related Art

It is known that energy-based therapies can be applied to tissuethroughout the body to achieve numerous therapeutic and/or aestheticresults. There remains a continual need to improve on the effectivenessof these energy-based therapies and provide enhanced therapeutic resultswith minimal adverse side effects or discomfort.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the various devices,systems and methods presented herein are described with reference todrawings of certain embodiments, which are intended to illustrate, butnot to limit, such devices, systems, and methods. It is to be understoodthat the attached drawings are for the purpose of illustrating conceptsof the embodiments discussed herein and may not be to scale.

FIG. 1 shows a cross-sectional view of the skin, including schematicallydemarcated target and non-target tissues, according to one embodiment.

FIG. 2A shows another cross-sectional view of the skin includingadditional features of interest.

FIG. 2B shows a cross-sectional view of the skin with apocrine andeccrine sweat glands.

FIG. 2C shows a cross-sectional view of the skin and particular regionsof the skin where treatment may be desired.

FIG. 3A shows a device having an energy applicator according to oneembodiment.

FIG. 3B shows a microwave generator for supplying the applicator withmicrowave energy according to one embodiment.

FIG. 4 shows a needle injecting fluid near the base of a sweat gland andtarget tissue according to one embodiment.

FIG. 5 shows an isometric view of a non-invasive energy delivery devicecomprising multiple microwave antennas electrically connected to amicrowave generator according to one embodiment.

FIG. 6 shows a cross-sectional side view of the non-invasive energydelivery device of FIG. 5 delivering energy into the skin.

FIG. 7A shows a monopole antenna according to one embodiment.

FIG. 7B shows a dipole antenna according to one embodiment.

FIG. 7C shows a helical antenna according to one embodiment.

FIG. 7D shows a loop antenna according to one embodiment.

FIG. 7E shows an antenna having a shaped outer conductor according toone embodiment.

FIGS. 7F-7G illustrate a horn antenna according to one embodiment.

FIG. 8A shows a cross-sectional view of an antenna having an innerconductor disposed within a coaxial cable according to one embodiment.

FIG. 8B shows a coiled antenna having a coiled conductor element formedentirely from a coaxial cable according to one embodiment.

FIG. 8C shows a coiled antenna having a coiled conductor element formedfrom an inner conductor according to one embodiment.

FIG. 9 shows a cross-sectional view of a slot antenna according to oneembodiment.

FIG. 10A shows a cross-sectional view of a target tissue having a zoneof thermal treatment according to one embodiment.

FIG. 10B shows a time-temperature curve illustrating the temperature atwhich a skin undergoing treatment would be expected to burn.

FIG. 11A shows an isometric view of a non-invasive energy deliverydevice comprising multiple microwave antennas electrically connected toa microwave generator according to one embodiment.

FIG. 11B shows a schematic view of a cooling source located remotelyfrom an energy source and energy applicator according to one embodiment.

FIG. 12 shows a side view of a vacuum pulling and holding skin accordingto one embodiment.

FIG. 13 shows an example of a typical skin fold.

FIG. 14 shows a skin fold being treated by an energy delivery devicecomprising two energy delivery elements according to one embodiment.

FIG. 15 shows a skin fold being treated by two slot antennas positionedon two sides of the skin fold according to one embodiment.

FIG. 16A shows a perspective view of a suction element according to oneembodiment.

FIG. 16B shows an alternate perspective view of the suction element ofFIG. 16A.

FIG. 17 shows one embodiment of a representative grid indicating targettreatment sites “A” and target treatment sites “B” that could be usedover a skin area to identify specific areas of treatment.

FIGS. 18A, 18B, 18C, 18D and 18E show a variety of patterns illustratingspecific areas of treatment and non-treatment sites that could be usedover an area of skin.

FIG. 19 shows three templates to be used in a staged treatment, whereineach template is configured to allow treatment to a different portion ofthe overall treatment area according to one embodiment.

FIG. 20 shows a schematic of a microwave applicator system includingwaveguide antenna and tissue capture according to one embodiment.

FIG. 21 shows a schematic of an underside of a waveguide applicatorsystem including waveguide antenna and tissue capture according to oneembodiment.

FIG. 21A shows a side perspective view of a microwave applicatorincluding a handle according to one embodiment.

FIG. 21B shows an alternate perspective view of the microwave applicatorof FIG. 21A including a handle and housing.

FIG. 22 shows a schematic of a microwave applicator system including aslot antenna according to one embodiment.

FIG. 22A shows a schematic of a microwave applicator system including aslot antenna and various adjustable dimensional parameters according toone embodiment.

FIG. 23 shows a schematic of an underside of a waveguide applicatorsystem including slot antenna and tissue capture according to oneembodiment.

FIG. 24 shows a schematic of a microwave applicator system including aplurality of slot antennas and tissue capture according to oneembodiment.

FIG. 24A shows a computer generated image created by simulating twoantennas having an in-phase drive operation and focused on treatment ofa single area.

FIG. 24B shows a computer generated image created by simulating twoantennas having an in-phase drive operation with a 103 degree phaseshift between drive signals of a first antenna and a second antenna.

FIG. 24C shows a computer generated image created by simulating of twoantennas having an in-phase drive operation with a 170 degree phaseshift between drive signals of a first antenna and a second antenna.

FIG. 24D shows a computer generated image created by simulating twoantennas having an in-phase drive operation with a 155 degree phaseshift between drive signals of a first antenna and a second antenna.

FIG. 25 shows a schematic of an underside of a waveguide applicatorsystem including a dual slot antenna and tissue capture according to oneembodiment.

FIG. 26 shows a schematic of a microwave treatment system according toone embodiment.

FIG. 27A shows a histological cross-section of a normal porcine apocrinegland at the dermal/hypodermal interface.

FIG. 27B shows a histological cross-section of a porcine sweat gland oneweek after microwave therapy.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Overview of Treatments

Disclosed herein are methods, apparatuses and systems for non-invasivedelivery of energy-based therapy, which in one embodiment is microwavetherapy. The energy-based therapy can be delivered to various targettissues to achieve numerous therapeutic and/or aesthetic results. Theterms treatment, treatment effect, treating area/region may relate tothe treatment of the target tissue and/or any target structures, whereinthe treatment itself may impact the target tissue and/or targetstructures in one or more of the following ways: modification,deactivation, disablement, denervation, damage, electroporation,apoptosis, necrosis, coagulation, ablation, thermal alteration anddestruction. More specifically, reaching a temperature in the targettissue and/or target structures therein of at least about 50° C. or morein one embodiment can be used to achieve a desired treatment effect.Additionally, in one embodiment delivering thermal energy sufficient toheat the target tissue to about 60° C. or more can be used to result inthermal ablation of the target tissue.

FIG. 1 shows a cross-sectional view of the skin, its three primarylayers, the hypodermis 100, dermis 101, and epidermis 102, and internalstructures. In certain embodiments it may be desirable to concentratethe treatment within a particular region of dermal 101 and subcutaneous100 tissue (also referred to herein as the hypodermis) in which thetarget histological structures reside (e.g., “target tissue”), whiledoing minimal damage to the tissue above the target tissue in theepidermis 102 and dermis 101 (e.g., “superficial non-target tissue” 103)and tissue structures within the hypodermis 100 (e.g., “deep non-targettissue” 104) as illustrated in FIG. 1 with the various demarcated areasin dotted lines. One or more of the structures may be targeted by themethods and devices disclosed herein.

FIG. 2A is another cross-sectional view of the skin, additionallyillustrating other body structures, including an eccrine gland 106. Aswill be discussed further below, eccrine glands 106 are coiled tubularglands which can be found in the deep dermal 101 layers and/or the upperportion of the hypodermis 100. Several million glands are generallypresent over the surface of the skin, particularly the palms and soles,hairless areas, and axillae. While one gland 106 may have a single duct109 with a corresponding opening to the surface of the skin, some typesof gland variations include twin glands having a common terminalexcretory duct, or a single gland having a plurality of excretory ducts(not shown).

FIG. 2B illustrates a cross-sectional view of the skin with bothapocrine 107 and eccrine 106 (merocrine) sweat glands. As will bediscussed further below, eccrine sweat glands 106 are long tubularextensions from the epidermis 102 which coil into a ball-shaped massgenerally in the dermis 101. Apocrine glands 107 are in, for example,the axilla, perianal and pubic areas, scrotum, labia majora and aroundthe nipples. They lie generally in the deep dermis 101 and hypodermis100 and their ducts 102 terminate in hair follicles. There aremyoepithelial cells between the secretory cells of eccrine 106 andapocrine 107 glands and their basement membrane.

Sebaceous glands 108 are pear-shaped glands which empty their oilyproduct, sebum, into the upper portion of hair follicles. Even whereseveral glands open into the same follicle, they are situated at thesame level, in the superficial region of the dermis 101. Some sebaceousglands 108 exist independently of hair follicles, opening directly onthe skin surface: the lips, the eyelid, the glans penis, the internalfold of the prepuce, the labia minora, and the nipple, for example.

FIG. 2C shows a cross-sectional view of the skin (as in FIG. 2A)illustrating that in certain embodiments it may be desirable toconcentrate the treatment within a particular region of dermal 101 andhypodermis 100 tissue in which the target histological structures reside(e.g., “target tissue” 105) while doing minimal damage to the tissueabove the target tissue 105 in the epidermis 102 and dermis 101 (e.g.,“superficial non-target tissue” 103) and tissue structures within thehypodermis 100 (e.g., “deep non-target tissue” 104), as shown above totarget the eccrine glands 107.

Depending on the area of the body, the target tissue 105 region maybegin anywhere from about 0.5 mm to about 4 mm beneath the skin'ssurface and end anywhere from about 1 mm to about 10 mm beneath theskin's surface in some embodiments. Depending on the area of the body,the superficial non-target tissue 103 region may begin at the skinsurface and end anywhere from about 0.5 mm to about 4 mm beneath theskin's surface in some embodiments. Depending on the area of the body,the deep non-target tissue 104 region may begin anywhere from about 1 mmto about 10 mm beneath the skin's surface in some embodiments.

The specific types of tissue structures that will be selected fortherapy will depend on the specific therapy or therapies desired. Forexample, microwave energy can be delivered to the eccrine 106 orapocrine 107 sweat glands to reduce sweating in a patient. Additionally,apocrine glands 107 can be treated to achieve a reduction in body odor.In another embodiment, microwave therapy can be used to shrink collagenin the skin for the purposes of skin tightening, wrinkle reductionand/or body sculpting. In other embodiments, microwave therapy can beused to treat hair follicles, acne, cellulite, vasculature such asvaricose veins and telangiectasias, and various other structuresdisclosed in the application. Accordingly, the location of the targettissue 105 and non-target tissues 103, 104 may require adjustment basedon the specific therapy desired.

Clinical Indications

Various non-limiting examples of anatomical structures and clinicalindications that can be treated by the systems and methods disclosedherein are listed. In some embodiments, a plurality ofstructures/disorders can be treated in the same treatment session.

Hyperhidrosis

Hyperhidrosis is a clinically diagnosed disorder in which there isexcessive secretion of sweat from the sweat glands. The excessivesweating, which is thought to result from the over activity of thesympathetic nervous system, usually occurs in the palms, soles, andaxillae. Palmar hyperhidrosis is a condition of excessive sweating inthe hand. This condition is often exhibited in cold, wet handshakes.Plantar hyperhidrosis is a condition of excessive sweating in the foot.This condition may cause blisters and fungal infections. Axillaryhyperhidrosis is a condition of excessive sweating in the armpit. Suchexcessive sweating is not only socially embarrassing but may even causestaining and rotting of clothes.

The sweat glands in the body are comprised of the apocrine 107 andeccrine 106 glands. Eccrine sweat glands 106, which lie superficially inthe dermis layer 101 of the skin, are located all over the body so thatthey can secrete sweat to regulate body heat and temperature. Apocrineglands 107, which exist within the hypodermis 100 and border on theinterface between the hypodermis 100 and dermal layer 101, secrete anoily, milky, protein-rich product into the follicles. Bacterialdigestion of apocrine sweat is largely responsible for osmidrosis orbromohidrosis (i.e., body odor), which can be most pronounced in thefoot and underarm area.

There are various treatments used for treating hyperhidrosis. Forexample, chemical antiperspirants and deodorants are commonly used as amatter of personal hygiene. Antiperspirants are aluminum based saltsthat mechanically block the sweat gland ducts, thereby preventing sweatfrom reaching the skin surface. Deodorants change the pH of the skinsurface, thereby minimizing the presence of smell inducing bacteria.Because the effects of both of these products are temporary and canirritate the skin in some users, these products are suboptimal solutionsto cases of excessive sweating.

In addition to antiperspirants and deodorants, other topicalpreparations have been used to treat hyperhidrosis. For example,glutaraldehyde and tannic acid have been used in the treatment ofplantar and palmar hyperhidrosis. However, these treatments havegenerally lost favor because they may cause an unsightly browning of theskin.

Anticholinergic drugs have also been applied both topically andsystemically to treat hyperhidrosis. These agents block the sympatheticstimulation of the eccrine glands 148 by inhibiting the action ofacetylcholine at the nerve synapse. Use of these drugs is limitedbecause of the systemic side effects they cause, including dry mouth,urinary retention, constipation, and visual disturbances such asmydriasis and cycloplegia. Moreover, topical anticholinergics sometimeshave difficulty absorbing into the skin in sufficient quantities toaffect the cholinergic nerve endings.

Some patients with hyperhidrosis have resorted to surgical treatmentssuch as sweat gland excision and thoracic sympathectomy. For example,U.S. Pat. No. 5,190,518 to Takasu, which is herein incorporated byreference in its entirety, discloses an ultrasonic surgical device fordisabling and excising sweat glands. These treatments may provide for alonger duration of alleviation from hyperhidrosis. However, thesetreatments are rarely utilized due to their invasive nature, adverseconsequences and cost. For example, surgery may cause contractures ofthe skin, muscle or other surrounding tissue. Sympathectomy may resultin complications including infection, pneumothorax, Homer's syndrome,and compensatory hyperhidrosis of the trunk, back and thighs.

Recently, botulinum type-A neurotoxin (e.g., BOTOX™) has provedeffective in treating hyperhidrosis in some patients. BOTOX is commonlyused by dermatologists to denervate the neuroglandular junctions betweenthe autonomic nerves and the sweat glands. With the nerve connectionsdisabled, acetylcholine is prevented from reaching the eccrine sweatglands 106, thereby disabling a component of the hyperhidrosis patient'soveractive sympathetic nervous system. This treatment, however, is notwithout its downsides. Botulinum toxin is one of the most lethalsubstances on earth and, consequently, injecting it in a patient's bodyis full of risk. Additionally, since the apocrine sweat glands 107 areinnervated by adrenergic nerves, which are not blocked by botulinumtoxin, injections of botulinum toxin do not have a clinical impact onthe body odor caused by the secretions from apocrine glands. Botulinumtoxin treatment also requires multiple, painful injections with aneedle. Furthermore, the results of this treatment last only a fewmonths, thereby necessitating repeated costly and painful treatments.

In light of the shortcomings of the aforementioned approaches, aminimally-invasive, convenient, effective, long-lasting treatment withfew side effects would be a desirable alternative for treatinghyperhidrosis.

Wrinkles

Wrinkles are also a very common skin condition precipitated by factorsincluding the aging process, UV light exposure, and smoking. As a personages, the epidermal cells become thinner and less adherent to eachother. The thinner cells make the skin look noticeably thinner. Thedecreased adherency of the cells decreases the effectiveness of thebarrier function allowing moisture to be released instead of being keptin the skin, causing dryness. The number of epidermal cells decreases byapproximately 10% per decade in some patients and divide more slowly aswe age making the skin less able to repair itself quickly.

The effects of aging on the dermal layer 101 are significant. Not onlydoes the dermal layer 101 thin, but also less collagen is produced, andthe elastin fibers that provide elasticity wear out. These changes inthe scaffolding of the skin cause the skin to wrinkle and sag. Also,over time, sebaceous glands 108 get bigger but produce less sebum, andthe number of sweat glands decreases. Both of these changes lead to skindryness.

The rete-ridges of the dermal-epidermal junction flatten out in theaging process, making the skin more fragile and easier to shear. Thisprocess also decreases the amount of nutrients available to theepidermis 102 by decreasing the surface area in contact with the dermis101, also interfering with the skin's normal repair process.

In the subcutaneous layer 100, fat cells get smaller with age. Thisleads to more noticeable wrinkles and sagging, as fat cells cannot “fillin” the damage from the other layers.

Ablation of the epidermis 102 can destroy older, damaged epidermalcells, bringing to the surface newer epidermal cells and stimulatingcollagen formation. Additionally, thermal contracture of deeper collagenfibers can induce overall skin contracture. For instance, contracture ofdeep dermal collagen and subcutaneous fibrous septae has been suggestedas a potential mechanism of action for another thermal wrinkle treatmentsystem marketed by Thermage, Inc. (Hayward, Calif.).

Bromohidrosis

Especially malodorous sweat (bromohidrosis) can occur, especially in theaxilla and feet. Bromohidrosis, which is often associated withhyperhidrosis, may occur due to one or more of the following: apocrinegland 107 dysfunction, bacterial and fungal infections, fatty aciddecomposition producing a distinctive odor, ingestion of certain foods,and arsenic ingestion. Various treatments are available but are notalways ideal or practical, including general cleaning of the body andfrequent bathing, changing socks and under wear repeatedly, wearinglight clothes, avoidance of excessive sweating, avoidance of excessiveconsumption of certain types of food such as proteins, garlic, andspices, aeration of the problematic area, using dusting powdersparticularly for the feet before dressing the socks, using soaks for thefeet such as potassium permanganate 1:2000 or formaldehyde solution, andusing deodorants and antibacterial antiseptic soap.

Chromohidrosis

Chromohidrosis is abnormally colored sweat due to dysfunction of theapocrine glands 107. Common sites include the face, where the color ofsweat may be black, green, blue or yellow in some cases.

Acne

Acne is a disorder of the pilosebaceous unit, which is made up of a hairfollicle, sebaceous gland, and a hair. These units are found everywhereon the body except on the palms, soles, top of the feet, and the lowerlip. The number of pilosebaceous units is greatest on the face, upperneck, and chest. Sebaceous glands 108 produce a substance called sebum,which is responsible for keeping the skin and hair moisturized. Duringadolescence, sebaceous glands 108 enlarge and produce more sebum underthe influence of hormones called androgens. After about age 20, sebumproduction begins to decrease. A bacteria, known as Propionibacteriumacnes, is a normal inhabitant of the skin. It uses sebum as a nutrientfor growth, and therefore increases in follicles during puberty.

People with acne may have more Propionibacterium acnes in theirfollicles than people without acne. The presence of bacteria attractswhite blood cells to the follicle. These white blood cells produce anenzyme that damages the wall of the follicle, allowing the contents ofthe follicle to enter the dermis. This process causes an inflammatoryresponse seen as papules (red bumps), pustules, and nodules. Thebacteria also cause the formation of free fatty acids, which areirritants, increasing the inflammatory process in the follicle.

Sebum produced by the sebaceous gland 108 combines with cells beingsloughed off within the hair follicle and “fills up” the hair follicle.When the follicle is “full”, the sebum spreads over the skin surfacegiving the skin an oily appearance. When this process works correctly,the skin is moisturized and remains healthy.

Problems arise when the sebum is trapped in the hair follicle. Forreasons that are still unclear, some hair follicles become obstructed.The sebum is produced but gets trapped on the way out, and the cellsthat are normally sloughed off become “sticky”, plugging up thefollicle. The process of obstructing follicles is called comedogenesis.It causes some follicles to form a type of acne called comedones, alsoknown as blackheads and whiteheads.

Various medications have been used for the treatment of acne, includingoral and topical retinoids, antibiotics, exfoliants, and surgicaldermabrasion, which results in ablation of the stratum corneum layer ofthe epidermis. More recently, focal thermal therapy has been introduced.Heating individual sites of obstructed follicles and sebaceous glands108 kills the bacteria within the gland, resulting in reducedinflammation.

Cellulite

Cellulite is the dimpling of the skin, especially in the thigh andbuttock regions. Cellulite generally affects women much more frequentlythan men. Although many therapies that presume cellulite is caused by anabnormality of adipose tissue have gained recent popularity, the basicpathophysiology of cellulite has not been clearly identified.Histopathologic samples have shown cellulite may be the result ofirregular extrusion of adipose tissue from the hypodermis 100 into thedermis 101. Traditional therapies such as diet and exercise, and moreinvasive therapies such as panniculectomy or liposuction each haveseveral disadvantages. A non-invasive way to target dermal adiposetissue without significantly affecting other structures is thus verydesirable.

Hair Growth

Unwanted hair growth may be caused by a number of factors including agenetic predisposition in the individual, endrocrinologic diseases suchas hypertrichosis and androgen-influenced hirsuitism, as well as certaintypes of malignancies. Individuals suffering from facial hirsuitism canbe burdened to an extent that interferes with both social andprofessional activities and causes a great amount of distress.Consequently, methods and devices for treating unwanted hair and othersubcutaneous histological features in a manner that effects a permanentpathological change are very desirable.

Traditional treatments for excessive hair growth such as depilatorysolutions, waxing and electrolysis suffer from a number of drawbacks.Depilatory solutions are impermanent, requiring repeated applicationsthat may not be appropriate for sensitive skin. Although wax epilationis a generally safe technique, it too is impermanent and requiresrepetitive, often painful repeat treatments. In addition, wax epilationhas been reported to result in severe folliculitis, followed bypermanent keloid scars. While electrolysis satisfactorily removes hairfrom individuals with static hair growth, this method of targetingindividual hairs is both painful and time consuming. In addition, properelectrolysis techniques are demanding, requiring both accurate needleinsertion and appropriate intensities and duration. As with waxepilation, if electrolysis techniques are not performed properly,folliculitis and scarring may result.

Recently developed depilatory techniques, utilizing high intensity broadband lights, lasers or photochemical expedients, also suffer from anumber of shortcomings. In most of these procedures, the skin isilluminated with light at sufficient intensity and duration to kill thefollicles or the skin tissue feeding the hair. The impinging lighttargets the skin as well as the hair follicles, and can burn the skin,causing discomfort and the potential for scarring. Further, laser andother treatments are not necessarily permanent and may require repeatedapplications to effect a lasting depilation. Finally, efficacy of theselight based therapies relies on a differential between the melanin inthe skin and the melanin in the hair. Heat is generated to kill the hairfollicles by light absorption of melanin. Thus, in patients with lighthair, not enough melanin is present in the hair follicle to generateablative heat. Conversely, in dark skinned patients, melanin in the skinmay absorb so much light that skin ablation occurs simultaneously withhair follicle ablation.

Varicose Veins and Telangiectasias

Like hair follicles, spider veins are subcutaneous features. They existas small capillary flow paths, largely lateral to the skin surface,which have been somewhat engorged by excessive pressure, producing thecharacteristic venous patterns visible at the skin surface. Apart fromthe unsightly cosmetic aspect, telangiecstasia can further have moreserious medical implications. Therefore, methods and devices fortreating spider veins and other subcutaneous histological features in amanner that effects a permanent pathological change to the appropriatetissues are highly desirable.

The classical treatment for spider veins is sclerotherapy, wherein aninjection needle is used to infuse at least a part of the vessel with asclerotic solution that causes blood coagulation and blockage of theblood path. With time, the spider veins disappear as the blood flowfinds other capillary paths. Since there can be a multitude of spiderveins to be treated over a substantial area, this procedure istime-consuming, tedious, and often painful. It is also of uncertaineffectiveness in any given application and requires a substantial delaybefore results can be observed.

Another procedure for the treatment of shallow visible veins, which issimilar to techniques used in depilation, involves the application ofintense light energy for a brief interval. This technique exposes theskin surface and underlying tissue to concentrated wave energy, heatingthe vein structure to a level at which thermocoagulation occurs. Inparticular, these energy levels are so high that they cause discomfortto some patients, and can also be dangerous to those in the vicinity,unless special precautions are taken. In addition, some patients can besinged or burned, even though the exposure lasts only a fraction of asecond.

Due to the serious problems that the subcutaneous abnormalities cancreate in individuals, there is a general need to be able to treat suchfeatures in a manner that effects beneficial pathological change withoutadverse side effects or discomfort. An optimal therapeutic techniqueshould effect a permanent pathological change without requiring repeatedapplications to reach the desired effect. Moreover, these proceduresshould be non-invasive, should cover a substantial target area that isnot limited to a single hair follicle or spider vein, and should makeoptimum use of the energy available. Finally, pathological changesshould occur only in the targeted feature, and not in intervening orunderlying layers.

Benign and Malignant Skin Lesions and Infections

Numerous malignant and pre-malignant skin lesions, including actinickeratosis, basal cell carcinoma, squamous cell carcinoma, and melanoma,and benign skin lesions such as cysts, warts, nevi, café au lait spots,and vascular lesions would also benefit from a non-invasive localizedtreatment. Furthermore, skin and nail infections from bacteria, viruses,fungi, or parasites, could also benefit from a non-invasive localtreatment method.

Neurologic Disorders

The hypodermis layer 100 is innervated by sensory nerve endings. Anon-invasive local treatment for hyperesthesia, e.g., from neurologicdisorders such as, for example, multiple sclerosis and herpes zoster,would also be desirable.

In combination with the thermal treatments disclosed herein, protectivetreatments can be employed to prevent damage or pain to non-targettissue. In one embodiment, thermal protective treatments may be used.For example, surface cooling can be applied to protect the epidermallayer 102 and portions of the dermal layer 101 of the skin while deeperregions of skin tissue are heated via energy delivery. Various types ofactive and passive cooling can be configured to provide this thermalprotection to non-target tissue 103, 104.

While the above clinical indications have generally focused on theintegumentary system (i.e., the skin and associated structures), one ofordinary skill in the art will appreciate that various other anatomicalstructures can be treated using the disclosed systems and methods. Forexample, visceral tissues and organs such as the brain, lungs, heart,kidneys, stomach, intestines, gallbladder, pancreas, aorta and otherarteries, veins, bladder, prostate, ovaries, uterus, fallopian tubes canalso be treated using the embodiments of the present application.

The delivery of therapy may also be facilitated by administering many ofthe treatments disclosed herein in one or more spatial configurations orskin geometries. For example, treatment can be directed perpendicular tothe skin surface, parallel to the skin plane or at some angle inbetween. Additionally, the skin can be oriented in variousconfigurations to achieve the desired energy delivery. For example,energy can be delivered to the skin in a flat, planar configuration, inan elevated orientation or in a folded geometry. Additionally, suctioncan be applied to the skin to achieve a particular orientation orgeometry.

Microwave therapy may also be facilitated by administering treatmentover multiple stages and in a patterned arrangement. This approach canenhance the body's healing response, making for a quicker recovery withfewer complications. Various templates are disclosed to assist inadministering a staged and patterned treatment. Microwave therapy mayalso be facilitated by the introduction into the treatment zone ordirectly into the target tissues of exogenous microwave absorbers. Somesubstances, such as graphite, carbon black, or ferrite willpreferentially absorb microwaves and increase the local thermal effect.

With reference to the drawings disclosed in this specification, theparticulars shown are by way of example and for purposes of illustrativediscussion of certain embodiments. In this regard, not all structuraldetails may be shown in detail. Accordingly, it should be understoodthat the application is not limited to the details of construction andthe arrangement of components set forth in the descriptions orillustrations provided herein. Additionally, it should be understoodthat the terminology used herein is for the purpose of description andshould not be regarded as limiting.

The embodiments disclosed herein relate to the treatment of dermal andsub-dermal tissue structures via the transcutaneous delivery of energy.While microwave energy is generally preferred, it should be understoodthat many other energy modalities can be used to achieve the intendedtherapy. For example, it may be possible for the apparatuses and systemsdisclosed herein to be configured to deliver one or more of thefollowing modalities: electromagnetic, x-ray, RF, DC, AC, microwave,ultrasound, including high-intensity focused ultrasound (HIFU),radiation, near infrared, infrared, and light/laser. Non-limitingexamples of embodiments directed to non-microwave as well as microwavetreatment of the skin and other organs can be found for example, in U.S.Provisional Patent Application No. 60/912,899, entitled “Methods andApparatus for Reducing Sweat Production,” filed Apr. 19, 2007 and U.S.Provisional Patent Application No. 61/013,274, entitled “Methods,Delivery and Systems for Non-Invasive Delivery of Microwave Therapy,”filed Dec. 12, 2007, both of which are incorporated by reference intheir entireties, particularly seen for example, in FIGS. 8-32 and pp.14-40 of Application No. 60/912,899. Further microwave systems andmethods that can be used with embodiments of the invention are disclosedin, for example, FIGS. 2-25 of App. No. 61/045,937 and the accompanyingdescription at pp. 11-18. The 61/045,937 application has also beenpreviously incorporated by reference in its entirety. Various tissuestructures may be targeted as listed above, including sweat glands,sebaceous glands, collagen, hair follicles, cellulite, and vasculaturethat supplies blood to any of the above.

The system illustrated in FIGS. 3A-B shows a device 110 having an energyapplicator 111 for non-invasively delivering microwave energy 112 to thetarget tissue layer 105 and a microwave generator 113 for supplying theapplicator 111 with microwave energy 112 via conduit 114 as shown inFIG. 3B. In this embodiment, the energy applicator 111 comprises atleast one antenna for delivering microwave energy 112 to the targettissue 105. The antennas would be configured, when the device is placedagainst or near the patient's skin, to heat and treat the target tissue105 and target structures within the target tissue 105. The treatedtarget tissue 105 could either be left in place to be resorbed by thebody's immune system and wound healing response or be extracted usingany number of minimally invasive techniques. Also illustrated is coolingplate 115 for preventing damage to superficial non-target tissue 103.

Microwave energy 112 is absorbed by the target tissue 105 by a processcalled dielectric heating. Molecules in the tissue, such as watermolecules, are electric dipoles, wherein they have a positive charge atone end and a negative charge at the other. As the microwave energy 112induces an alternating electric field, the dipoles rotate in an attemptto align themselves with the field. This molecular rotation generatesheat as the molecules hit one another and cause additional motion. Theheating is particularly efficient with liquid water molecules, whichhave a relatively high dipole moment.

Since microwave heating is particularly efficient when water moleculesare present in tissue, it may be desirable to have a relatively highwater content or molecule density at the target tissue or within thetarget structures. This high water content would result in greatermicrowave energy absorption and consequent heating at the point oftreatment. Moreover, this phenomenon will allow the preferential heatingof target tissue 105, thereby minimizing the impact to non-target tissue103, 104.

There are numerous ways in which water content in the target tissue 105can be achieved. For example, injecting a bolus of fluid 116 (e.g.,water, saline, etc.) into or near the target tissue 105 or targetstructures would render such areas more susceptible to microwavetreatment. FIG. 4 shows one embodiment of the injection of fluid 116proximate to the base of a sweat gland and target tissue 105. Whentargeting sweat glands, the patient can be induced to sweat in the areaof treatment (such as by raising the ambient temperature or thetemperature in the target area) in order to achieve higher water contentin the target structures. In any of these cases, the water dense sweatglands can be plugged to prevent any of the water/sweat from escapingthrough the sweat ducts. Sealing the gland ducts can be achieved byusing aluminum ion based topical products such as antiperspirants or anytype of biocompatible polymer coating. The addition of external water isnot required in some embodiments. Not to be limited by a particulartheory, sweat glands naturally have a relatively high water contentcompared to surrounding tissue which can allow the sweat glands topreferentially absorb microwave energy 112. Furthermore, sweat glandsgenerally have a higher concentration of ions (e.g., a greater ionicpotential) relative to surrounding tissue which also advantageously canallow for the preferential absorption of microwave energy with respectto the surrounding tissue.

One of ordinary skill in the art will also appreciate that tissue ofrelatively low water content (e.g., cellulite) can also bepreferentially targeted by microwave energy by aligning the e-field ofthe radiated signal to preferentially heat the low water content fatlayer. Further details regarding controlling the effect of microwaveenergy on target tissue are found in U.S. Provisional Patent ApplicationNo. 60/912,899, entitled “Methods and Apparatus for Reducing SweatProduction,” filed Apr. 19, 2007, U.S. Provisional Patent ApplicationNo. 61/013,274, entitled “Methods, Delivery and Systems for Non-InvasiveDelivery of Microwave Therapy,” and U.S. Provisional Patent ApplicationNo. 61/045,937, entitled “Systems and Methods for Creating an EffectUsing Microwave Energy in Specified Tissue,” filed Apr. 17, 2008,particularly seen for example, in FIGS. 26-51 and pp. 18-33 ofApplication No. 61/045,937.

As shown in FIG. 5, an apparatus for treating target tissue 105 withmicrowave energy can be configured to include a processor (not shown),an energy generator 113 connected to the processor, and a device 117operatively coupled to the generator. The device 117 can further includean energy delivery applicator 111 or energy delivery element such as anantenna for delivering energy to the target tissue. In an exemplifyingembodiment, a cable 114 (e.g., feedline) electrically connects thedevice to an energy generator 113. In other embodiments, the processor,the device, and/or the energy generator 113 can be connected wirelesslyvia, for example, radio frequency signals. In a preferred embodiment,the energy generator 113 is remotely located from the energy applicator111, wherein the generator 113 can be either stationary or mobile.Alternatively, the applicator 111 and generator 113 can be coupled suchthat they comprise a portable unit. Still alternatively, the applicator111 and generator 113 can be combined into a single unit.

FIG. 5 is an isometric view depicting one embodiment of a non-invasiveenergy delivery device 117 comprising multiple microwave antennas 120that are electrically connected to a microwave generator 113. In oneembodiment, the antennas 120 are contained in a substantially planarapplicator plate 121 sized for application against a target area of apatient's skin 119. In one embodiment, the device 117 and the applicatorplate 121 therein, can be sized and configured to substantially matchthe area of tissue being treated. Additionally, the applicator plate 121may be flexible to help the device 117 conform to the contours of thepatient's skin.

FIG. 6 is a cross-sectional side view of the device 117 of FIG. 5showing the delivery of energy 112 into the skin. In such multi-antennaembodiments, it may be useful to orient the antennas 120 along the sameplane in the same longitudinal direction to deliver energy in a planarfashion. As shown in FIGS. 5 and 6, four or five microwave antennas 120are positioned parallel to each other. In other embodiments, fewer orgreater microwave antennas 120 may be provided, for example, one, two,three, or at least four, five, six, seven, eight, nine, ten or more.With this planar configuration, energy 112 can be delivered to a largerarea of tissue in one treatment and in a more consistent fashion. Insome embodiments, the antenna(s) 120 may be similar to that described inU.S. Pat. No. 4,825,880 to Stauffer et al. or U.S. Pat. No. 6,330,479 toStauffer, which are both hereby incorporated by reference in theirentirety.

As discussed later in this specification, thermal protective measurescan be employed in conjunction with thermal treatments. As shown inFIGS. 5 and 6, the applicator plate 121 containing the antennas 120 maybe connected by a conduit 114 to the microwave generator 113, withcooling fluid passing through the conduit to and from the applicatorplate 121 from a coolant circulator 118. The cooling fluid creates aprotected zone 103 in the epidermis 102 of the patient, so that targettissue 105 below the protected zone is treated. Protected zone 104 deepto target tissue 105 is also illustrated.

The amount of energy 112 delivered to the target tissue 105 andconsequent extent of treatment effect can be adjusted based on thenumber of antennas 120, their specific configuration and the powerdelivered to each antenna 120. In one embodiment, a microwave energyoutput frequency ranging from 300 MHz to 20 GHz would be suitable forfeeding the energy delivery device with power. In one embodiment, amicrowave signal of anywhere from about 915 MHz to about 2450 MHz wouldbe preferential for yielding a treatment effect on tissue.Alternatively, a signal having a frequency ranging from about 2.5 GHz toabout 10 GHz may also be preferential in some embodiments. Additionally,solid state, traveling wave tube and/or magnetron components canoptionally be used to facilitate the delivery of microwave energy.

The delivery of energy 112 to the target tissue 105 can be facilitatedby antenna 120 designs that incorporate a low-loss dielectric elementthat can take the form of a stand-off between the antenna 120 andtissue, and/or also a fill-material (e.g., a dielectric filledwaveguide). Unlike other forms of electrical energy delivery, such asradiofrequency, where energy is typically transmitted through directelectrical contact between a metal conductor and body tissue, microwaveenergy can be delivered through a low-loss dielectric material. Aproperly configured dielectric element will not impede the microwaveenergy from radiating to adjacent tissue and can be utilized as a designtool to help optimize the delivery of energy to the target tissue overthe course of the treatment. Since the dielectric properties(permittivity and conductivity) of skin and underlying tissue can changeover the course of a treatment (e.g., as temperature rises) due to lossof moisture, a dielectric element that removes the antenna from directcontact with the skin can help maintain consistent energy delivery tothe target tissue by ensuring a consistent load. This is achieved sincethe dielectric properties of the load in closest proximity to theantenna (i.e., the dielectric element) remain relatively consistentduring a treatment compared to that of the skin and underlying tissue.In addition to improving consistency, a low-loss dielectric (e.g.,ceramic, PTFE, polyimid, etc.) placed between the tissue and antenna canbe utilized to maximize power transfer into the tissue. The dielectriccould be incorporated into the antenna itself (e.g., as a fillmaterial), as an external component of the energy delivery device orsystem (e.g., as a dielectric “block” between the antenna and tissue),or as a combination of both. Further details regarding antenna designsare discussed below.

With respect to antenna design, several possible antenna designs can beimplemented to achieve the energy delivery function disclosed herein. Insome embodiments, the antenna is built using a section of semi-rigidcoaxial cable—with the antenna at one end and a microwave generator atthe other end. The antenna is then connected to the generator with along section of flexible microwave cable. Also, in certain waveguideantenna embodiments, the waveguide antenna can include a section ofwaveguide tubing with an appropriate shape or geometry depending on thedesired clinical result.

The coaxial cable further comprises an inner conductor shaft and outerconductor. In configurations comprising a monopole antenna 122, asillustrated in FIG. 7A, an inner conductor element 123 extends from theinner conductor shaft 124 and beyond the outer conductor 125.Electromagnetic energy is radiated from the antenna 122 with anomnidirectional radiation pattern 126 around the circumference of thewire 125. In another embodiment shown in FIG. 7E, a conductive shield orsleeve 127 is added to the antenna 122 to choke off unwanted currentflow down the outer conductor 125 of the coaxial line, thus limitingproximally radiating electromagnetic fields. In dipole antenna 128configurations, as illustrated in FIG. 7B, the outer conductor 125 isexposed in such a manner that electric field lines stretch from theinner conductor element 123 to the outer conductor 125.

Depending on the performance desired of the antenna 120, the antenna mayoptionally comprise a helical antenna 129 shown in FIG. 7C, a loopantenna 130 shown in FIG. 7D, or a horn antenna 131 shown in FIGS. 7F-G.These alternative antenna configurations provide geometric radiatingpatterns. For example, as illustrated in FIG. 7E, the outer conductor125 may comprise a shaped element, such as a horn shape, to provide adirectional component to the field created between the inner conductorelement 123 and outer conductor 125. Optionally, as shown in FIG. 7G,the outer conductor element 125 and/or inner conductor element 123 maybe bordered by, coupled to or coated by a dielectric element to optimizethe energy delivery capabilities of the antenna.

In another embodiment relating to energy delivery to target tissue, theapplicator 312 comprises an antenna 132 connected to a coaxial cable 133that is coupled to a microwave power source (not shown). As illustratedin FIG. 8A, the antenna 132 further comprises an inner conductor 123disposed within the coaxial cable 133, wherein an inner conductorelement 123 extends beyond the distal end of the coaxial cable 133 toform a coiled conductor element. Also shown are cooling inlets 134 andoutlets 135 demarcated by arrows. The coiled conductor element providesa relatively flat structure which can be aligned with the skin surfaceto deliver an even amount of energy to a plane of target tissue. Theapplicator may optionally further comprise at its distal end a thinshield comprised of a polymer or ceramic. FIGS. 8B and 8C respectivelyillustrate additional embodiments 136, 137 of the coiled antennaconfiguration, wherein the coiled conductor element may comprise theentire coaxial cable 133 (FIG. 8B) or just the inner conductor 123 (FIG.8C).

In addition to the antenna designs disclosed above, several otherantenna designs may be employed in an apparatus for delivering microwavetherapy. FIG. 9 depicts a cross-sectional view of one embodiment of slotantenna 138 comprised of coaxial cable 133 and shielding 139. Thecoaxial cable 133, which is connected to a microwave generator (notshown), is comprised of an inner conductor 123 and outer conductor 125,wherein the inner conductor 123 and outer conductor 125 are coupledtogether with solder 140 at the distal portion 141 of the antenna 138.The outer conductor 125 comprises a circumferential slot 142 throughwhich the electromagnetic field of the antenna 138 radiates in anomnidirectional pattern. The shielding component 139 is used to directthe electromagnetic field toward the treatment area, thereby minimizingloss and maximizing efficiency, and to prevent stray radiation ofelectromagnetic fields. Since coaxial slot antennas 138 are fed in anunbalanced configuration, and are subject to proximal current flow downthe outer conductor, a proximally radiated electromagnetic field canpropagate longitudinally down the coaxial antenna, and may result in anundesirable treatment effect to the superficial non-target tissue 103,104 that sits adjacent to the antenna. To avoid this outcome, theproximal portion 143 of the antenna 138 can be bent away from thetreatment area such as at 144 such that the surface currents andaccompanying fields are directed away from the non-target tissue 103,104. Additionally, the electromagnetic field is prevented from migratingfurther along the coaxial cable and outside the antenna by electricallycoupling the shielding to the coaxial cable using conductive epoxy orsolder. These fields are retained within the housing of the antenna 138so that they can be redirected via the shielding to the treatment area.The slot antenna system may also include a cooling circuit 118 andcooling plate 115 as shown.

Various other types of microwave antennas can also be used with thepresent application, for example, waveguide, single or multiple slotantennas, printed slot antennas, patch antennas, and Vivaldi antennas.

Microwave Generator

The microwave generator 113 preferably includes a generator head, apower supply, and an isolator. The generator 113 may be configured tohave a frequency of between about 915 MHz to 15 GHz, more preferablybetween about 2.4 GHz to 9.2 GHz, such as about 2.45 GHz and 5.8 GHz,and have an output power maximum, in some embodiments, of no more thanabout 300 W, 200 W, 100 W, 75 W, or less.

Waveguide Antenna

In some embodiments, the system includes a waveguide antenna 145 (asshown, for example, in FIG. 20). The antenna preferably has a resonantfrequency of between about 915 MHz to 15 GHz, more preferably betweenabout 2.4 GHz to 9.2 GHz, such as about 2.45 GHz and 5.8 GHz in someembodiments.

The waveguide antenna 145 preferably has a cross-sectional sizeconfigured to the desired operational frequency and field configurationof the waveguide 145. Generally, lowest-order Transverse Electric (TE)modes are utilized (e.g., TE₁₀), although others are possible, such asTransverse Magnetic (TM), Transverse ElectroMagnetic (TEM), evanescent,or a hybrid mode. For example, the width and height (rectangular) ordiameter (circular) waveguide geometry correlate with the operationalfrequency and field configuration of the waveguide 145. Additionalparameters, such as the fill material, the type and placement of feed,and the use of mode filtering affect the operational frequency and fieldconfiguration of a waveguide 145. As will be appreciated by one ofordinary skill in the art, a transverse mode of a beam ofelectromagnetic radiation is a particular intensity pattern of radiationmeasured in a plane perpendicular (i.e., transverse) to the propagationdirection of the beam. Transverse modes occur in microwaves confined toa waveguide 145.

Transverse modes occur because of boundary conditions imposed on thewave by the waveguide 145. The allowed modes can be found by solvingMaxwell's equations for the boundary conditions of a given waveguide145. Transverse modes are classified into different types. TE modes(Transverse Electric) have no electric field in the direction ofpropagation. TM modes (Transverse Magnetic) have no magnetic field inthe direction of propagation. TEM modes (Transverse ElectroMagnetic)have no electric or magnetic field in the direction of propagation.Hybrid modes are those which have both electric and magnetic fieldcomponents in the direction of propagation. An evanescent field is atime-varying field having an amplitude that decreases monotonically as afunction of transverse radial distance from the waveguide 145, butwithout an accompanying phase shift. The evanescent field is coupled,i.e., bound, to an electromagnetic wave or mode propagating inside thewaveguide 145.

The length of the waveguide 145 can be adjusted such that the physicallength of the waveguide 145 corresponds to an electrical length that isa half-wavelength multiple of the guided wavelength 145 at the desiredoperational frequency. This allows an efficient match from the waveguide145 feed into the load.

The waveguide 145 can have a wide variety of cross-sectional geometriesdepending on the desired clinical objective and geometry of theparticular anatomical area to be treated. In some embodiments, thewaveguide 145 has a rectangular, circular, elliptical, or hexagonalcross-sectional geometry.

In some embodiments, the coaxial feed can be placed between about 0 mmto a distance equal to the guided wavelength (λ_(g)) with an insertiondepth of 1 mm to 100 mm. The placement is most preferably optimized forefficient transfer of power from coaxial feed to waveguide. In someembodiments, the coaxial feed has an insertion depth of between about 5%to 95% of the depth of the waveguide 145. In some embodiments, thecoaxial feed has an insertion depth of at least about 80% of the depthof the waveguide 145.

To have the desired energy density in the region of target tissue 105,the antenna 120 can be within 0.5-5 mm of the skin (e.g., between about1.5-2 mm, such as about 1.75 mm) in some embodiments, or within severalwavelengths of the skin at a given operational frequency in otherembodiments. This distance may be referred to herein as the antennastandoff height. Variation of the standoff height affects the spread ofthe microwave radiation. With a very large standoff, a reduced energydensity over a larger volume is achieved. Conversely, with little to nostandoff height the energy density is generally much higher over asmaller volume. To achieve therapeutic energy density levels with alarge standoff, significantly increased input power levels arenecessary. The absorption pattern of the microwave energy at depth intissue, strongly influenced by the standoff, directly influences therelative safety margin between target 175 and non-target (deep) tissues104. Finally, standoff height causes large variation in the loadingconditions for the waveguide, with reflected power levels observed bythe waveguide antenna 145 changing with standoff changes. In someembodiments, if a coded waveguide 145 is used, the standoff height couldbe about zero or even negative (e.g., the skin could be within thewaveguide 145).

Dielectric Filler

Choice of dielectric filler material allows waveguides 145 of variouscross-sectional area to be utilized and propagated at a specific desiredfrequency. Cutoff frequency of a fixed size waveguide can be decreasedby utilizing larger dielectric constant materials. For a desiredtreatment size and specified frequency range of 2.4-9.2 GHz, dielectricfiller materials with a dielectric constant of K=2 to 30 are utilized.In some embodiments, a preferred dielectric constant is K=10.

Larger K value dielectric filler materials have a permittivity that iscloser to that of tissue, giving the potential for lower reflection ingeneral between the applicator/tissue interface. Some examples ofdielectric constants include the skin (K=35-40), fat (K=5-10), muscle(K=50), or water (K=80). In embodiments involving a cooling element 115or other barrier, the dielectric filler material may be selected basedon having a dielectric constant that matches well to the cooling element115 and skin.

Tuning Stub

In some embodiments, a microwave antenna system, e.g., a waveguidesystem, includes a metal, adjustable tuning stub that can be utilizedfor optimal power transfer into a given tissue to further minimizereflections for a given tissue load at a specific frequency. Thisenhancement can help account for variations in manufacturing andtolerance. Instead of having high tolerance requirements, which might becost prohibitive, each antenna can be tuned to achieve desiredfunctional characteristics. In some embodiments, the metal tuning stubcan be secured to a wall of the antenna (e.g., the waveguide 145) by asuitable means such as adhesion, a rivet, soldering, or the like. Thestub can be a cylindrical member depending from the top walltransversely to the waveguide 145 path and located substantially on thelongitudinal centerline of the waveguide. The stub can extend to variousdepths in the waveguide 145 and is sized and located accurately so as tooptimally match the impedance that the waveguide antenna 145 presents tothe generator 113, allowing efficient power transfer. The tuning stubadvantageously provides a reactive impedance substantially without aresistance component.

Array of Waveguides

Waveguide applicators can be placed in an array configuration forsimultaneous or sequential treatment of multiple sites. Additionally,the possibility exists for beneficial phased (constructive effect ofin-phase fields) operation of a waveguide array (similar to the twincoaxial slot antennas), as discussed elsewhere in the application.

Horn Antenna

In some embodiments, the aperture of the waveguide antenna can be flaredoutward in a distal direction to form a horn antenna configuration. Thiscan spread the energy dispersion more widely, as well as increase therobustness of the antenna to varying tissue loads (i.e., the antennawill match well with patient to patient variation in tissuecomposition). The wider footprint created by a flared antenna providesthe potential for an increased treatment size. The flare can alsoadvantageously increase the manufacturing tolerance for the waveguide.For example, a horn antenna with a desired frequency of 5.8 GHz may havea frequency range of about 5.5 to 6 GHz in some embodiments.

Enhancements

Protective Cooling

In thermal treatments of tissue, it may be beneficial to protect againstthe unnecessary and potentially deleterious thermal destruction ofnon-target tissue. This is particularly the case in sub-dermaltreatments since excess energy delivered to the epidermal 102 and dermal101 layers of the skin can result in pain, discomfort, drying, charringand edge effects. Moreover, drying, charring and edge effects tosurrounding tissue can impair a treatment's efficacy in some cases asthe impedance of desiccated tissue may be too high to allow energy totravel into deeper regions of tissue.

To avoid thermal destruction to non-target tissue and any complicationsassociated therewith, an energy delivery device can include a coolingelement 115 for providing a cooling effect to the superficial non-targettissue 103 (e.g., the epidermis 102 and portions of the dermis 101). Byconductively and/or convectively cooling the epidermis 102 and allowingthe cooling effect to penetrate into the dermis 102, the cooling element115 will establish a zone of thermal protection 103 for the superficialnon-target tissue as illustrated in FIG. 10A. With the cooling element115 providing this zone of protection 103, the target tissue 105 (e.g.,zone of thermal treatment 105 in FIG. 10A) can be treated with minimalrisk of thermal damage to non-target tissues 103, 104.

FIG. 10B above illustrates a time-temperature curve illustrating theskin temperature above which a burn would be expected (curve B) andbelow which no appreciable injury would occur (curve A). Therefore, itwould be very desirable that during energy treatment the cooling systemmaintain the non-target skin surface temperature (which can be measuredby the temperature sensing element as discussed elsewhere in theapplication) below curve B for a given treatment duration, as well asbelow curve A in some embodiments.

To further reduce the risk of pain and/or other uncomfortable sensationsassociated with thermal treatment, the cooling element 115 can furthercool the superficial non-target tissue 103 to create a numbing effect.Depending on the type of thermal treatment employed and the associatedneed for complementary cooling, the cooling treatment and resultingcooling and/or numbing effect may be applied before, during and/or afterthe thermal treatment. Protective cooling may also be applied in analternating fashion with the heating treatment to maximize energydelivery while minimizing adverse effects to non-target tissue 103, 104.

The cooling element 115 can take many forms. The cooling element 115 canbe a passive heat sink that conductively cools the skin, such as a layerof static, chilled liquid (e.g., water, saline) or a solid coolant(e.g., ice, ceramic plate), a phase change liquid selected which turnsinto a gas, or some combination thereof (e.g., a cylinder filled withchilled water). The cooling element 115 can also provide active coolingin the form of a spray or stream of gas or liquid, or aerosol particlesfor convective cooling of the epidermis 102. A thermo-electric cooler(TEC) or Peltier element can also be an effective active cooling element115. Alternatively, an active cooling element 115 can comprise athermally conductive element with an adjacent circulating fluid to carryaway heat.

The cooling element 115 can also be incorporated into the device as aninternal cooling component for conductively cooling non-target tissue103, 104. For example, an energy delivery device can couple a coolingcomponent 115 to the energy applicator, where the cooling component 115can actively or passively provide conductive cooling to adjacent tissue.When passive cooling is provided, the cooling component 115 may comprisea cold metal plate or block. When active cooling is provided, thecooling component 115 may comprise a thermally conductive element,wherein a chilled liquid (e.g., water, dry ice, alcohol, anti-freeze) iscirculated through the element's internal structure. For example, inmicrowave energy delivery devices that include a dielectric, thedielectric itself can be a cooling component. In another example, thecooling component 115 can be incorporated into the antenna 120 such thatit is adjacent to the dielectric.

As shown in FIG. 11A, a cooling component 115 can be incorporated intoan energy delivery device 146 comprising at least one microwave antenna120, such as described above. In this embodiment, fluid is used to cooladjacent skin tissue 119. This convective cooling can be enhanced by acoolant circulator 118 that could optionally be integrated within,coupled to or located remotely from the energy generator 113. As shownin FIG. 11B, the cooling circulator 118 is located remote from both theenergy source 113 and energy applicator 121. The properties andcharacteristics (e.g., medium, flow rate, temperature) of thecirculating fluid (gas or liquid) can be selected and modified toachieve the desired cooling effect in light of the amount and rate ofenergy delivered to the target tissue.

Any type of chilled fluid or refrigerant may be used. In someembodiments, a system optimized for the delivery of microwave energy mayavoid having ions in the coolant. Coolant with high ionic contentgenerally has a high conductivity, leading to microwave absorption andheating, disrupting the microwave field and altering the energy deliveryto the tissue. Some examples of low-loss coolant include deionized waterand/or one or more of the following: vegetable oil, such as peanut,canola, sunflower, safflower, or olive oil, distilled water and alcohol,or isopropyl alcohol. In one embodiment, the coolant used is isopropylalcohol, which advantageously allows for liquid cooling at lowertemperatures because the freezing point of isopropyl alcohol is lowerthan that of water. While liquid coolants have been described, gas andsolid coolants are also within the scope of the invention.

A cooling plate, in some embodiments, preferably includes one or more ofthe following functions: (1) it is thermally conductive, that is, itcontrols heat transfer rate between tissue and cooling fluid; (2) it isthin (e.g., less than about 1 mm, 0.75 mm, 0.5 mm, 0.25 mm, 0.20 mm orless in some embodiments) relative to the wavelength of the microwavesignal and has low electrical conductivity (e.g., sigma of less thanabout 0.5, such as less than about 0.01 in some embodiments) in order tomaximize the efficiency of power transfer into the tissue/thermalconductivity, to keep the waveguide 145 close to the skin and minimizestandoff height; (3) it is of adequate stiffness to eliminate bowingwhile conforming to the skin, thereby maintaining consistent cooling(via constant contact with skin and uniform flow geometries (4) it ismade of materials that are transparent to microwave energy (e.g.,non-reflective). A cooling plate may be made of any suitable material,for example, glass or a ceramic composite including about 96% alumina,or a pyrolytic carbon in some embodiments.

Low-loss cooling plate materials that meet permittivity range aredesirable. They can be solids or non-solids (e.g., water, oil). In someembodiments, ceramics such as alumina (K=10), zirconia, silica, aluminumsilicate, or magnesia may be used. In other embodiments, polymers, suchas silicone rubber (K=3), or a ceramic-polymer composite such aseccostock polymer can be utilized. Although specific materials have beendescribed, one skilled in the art will appreciate that the applicationis not limited to those materials listed.

In some embodiments, the cooling plate is preferably sufficiently thinto minimize undesirable microwave reflection. For example, in someembodiments, the cooling plate may be no more than about 10 mm, 9 mm, 8mm, 7 mm, 6 mm, 5 mm, 4 mm, 3 mm, 2 mm, 1 mm, 0.75 mm, 0.5 mm, or lessin thickness.

The interface between waveguide 145 (outer wall) and filling, in someembodiments, has minimal air gaps, such as less than about 3 mm, 2 mm,1.5 mm, 1 mm, 0.5 mm, or less to help avoid unwanted e-fields. Interfacebetween the waveguide cooling element 115 and less housing or coolingchamber should have no air gaps.

Flow Manifold

In some embodiments, the flow chamber of a cooling system includes inletand outlet reservoirs to achieve a consistent flow rate across the flowchamber. Reservoirs are located on either side of the flow chamber. Theinlet reservoir allows for the accumulation of coolant such that thefluid can flow through the cooling chamber at nearly the same rate atany point in the cooling chamber. This constant flow rate allows forconsistent cooling across the cooling plate, to provide a thermallyconductive barrier. The reservoir at the outlet helps to advantageouslyprevent fluid backup that would inhibit flow across the flow chamber.

The cooling circuit also preferably includes a temperature controlelement to cool or heat fluid to the desired temperature, and a pump.The pump may be a conventional pump within the circuit, or alternativelya pump that functions outside of the cooling circuit, such as a rollerpump.

The flow rate of the cooling fluid may be adjusted for any desiredcooling. In some embodiments, the flow rate can be between about 100 and1,500 ml/min, such as between about 200-600 ml/min, between about200-400 mL/min, or about 600 mL/min in certain embodiments. Thetemperature of the cooling fluid across the cooling plate is preferablybetween about −5° C.-40° C., such as between 10° C.-37° C., or about 10°C. or 22° C. in certain embodiments. The geometry and surface area ofthe cooling plate is preferably proportional with respect to the surfacearea and geometry of the body surface to be treated.

Geometries

In many of the embodiments disclosed herein, treatment is administeredtopically and/or in a minimally-invasive fashion to achieve the desiredtreatment effect on target tissue. In some of these embodiments, theskin is depicted as a flat, multilayer plane of tissue, whereintreatment can be administered to target tissue in a manner that issubstantially perpendicular to its planar surface. It should beunderstood that although a treatment may be disclosed with respect to aparticular skin geometry (e.g., perpendicular topical delivery,perpendicular percutaneous insertion, etc.), such treatment may beadministered with respect to any number or variety of geometries,including those discussed below.

Tissue Acquisition/Elevated Skin

In energy treatments involving the delivery of microwaves, for example,there is the risk that the delivered energy may penetrate too deeplyinto the body and cause harm to the deep non-target tissue 104,associated critical structures (e.g., blood vessels, lymph nodes, muscletissue, etc.) and body organs. Therefore, it may be beneficial toelevate the target tissue comprising portion of the skin from theunderlying tissue. Such elevation can be achieved through manualmanipulation by the clinician or facilitated using any number ofdevices. For example, as illustrated in FIG. 12, a vacuum 147 can beused to pull and hold the skin 119, thereby elevating it for treatment.Optionally, a vacuum-suction device 147 can be incorporated into anenergy delivery device such that suction and energy delivery can beapplied in unison.

In another embodiment, a tool utilizing a sterile adhesive caneffectively prop up the skin for treatment. More simply, however, aclinician can use any number of clamps, tongs or other devices toachieve and maintain skin elevation for and during treatment.

Folded Skin

In another skin geometry configuration, it may be beneficial to firstpinch and fold the patient's skin prior to delivering energy to thetarget tissue. Following the optional administration of a localanesthetic such as lidocaine (topically or subdermally), the patient'sskin can be grasped and pulled partially away such that the epidermis102, dermis 101 and subcutaneous layer 100 are separated from theunderlying skeletal muscle. Once separated, the skin could then befolded such that neighboring sections of the skin abut one anotherwherein the subcutaneous layer 100 of one side of the fold faces thesubcutaneous layer 100 of the other side of the fold. Isolating theseadjacent subcutaneous layers 100 results in a treatment zone that isdense with target tissue 152 and target 152 structures. FIG. 13 shows anexample of a skin fold 148. The skin fold 148 comprises a top 149, twosides 150 (only one shown), two edges 151 (only one shown) and a zone of“sandwiched” target tissue 152 along the longitudinal length of the fold(e.g., treatment zone).

Focusing treatment on the target tissue 152 rich region within the skinfold 133 will allow for a more efficient procedure as two adjacentlayers of target tissue can be treated in a single treatment.Additionally, treatment can be administered from one or moreorientations (e.g., both sides of the fold), which can result in a moreeffective and reliable treatment. Also, since the skin is being pulledaway from the body, damage to non-target structures 155 is minimized.Moreover, since the act of pinching or suctioning the skin fold 148 intoposition temporarily restricts blood flow to the folded tissue, there isless chance that the thermal energy delivered during treatment will bedissipated by blood flow. Additionally, the neural activity caused inthe skin by the folded configuration may reduce the patient's painsensation during treatment under the gate control theory of painmanagement (discussed below), which can be applicable for both vacuumlifting of the skin as well as manual “pinching” of the skin.

In one embodiment, as illustrated in FIG. 14, the skin fold 148 istreated from opposite sides by an energy delivery device comprising twoenergy delivery elements 154. The energy delivery elements 154 areconfigured to deliver energy to the treatment zone 148 in the middle ofthe fold. In the case of energy delivery devices that comprise one ormore microwave antennas 120 connected to one or more microwavegenerators 113, for example, as shown in FIG. 5 above, the microwaveenergy 112 can cross the outer epidermal layers 102 from each side ofthe skin fold and penetrate deep into the treatment zone 152. Tooptimize the delivery of microwave energy 112 to previously targettissue 105, a dielectric can optionally be used in this treatment. Alsoas shown previously and described in connection with FIG. 5, coolingelements 115 can also be used on the skin surface to create a zone ofprotection 155 for non-target tissue. Additionally, the device 153 canbe configured with a cooling element 115 and/or dielectric element oneither side of the skin fold 148 to stabilize the fold during treatment.

In another embodiment, treatment can be concentrated and localized atthe target tissue 152 using the summation effect of two or more energysignals. As illustrated in FIG. 15, antennas such as the slot antennas138 shown, can be positioned on either side (such as 139) of the skinfold 133 to deliver continuous microwave treatment from both sides ofthe skin fold. The energy waves from each antenna 138 can be phased suchthat the wave from a first antenna 138 can harmonize with the wave froma second antenna 138 and yield a cumulative treatment effect at the zoneof target tissue 152. The waves can also be synchronized such that theycancel one another out in areas where treatment is not desired (i.e.,non-target tissue). Accordingly, the optimal treatment would compriseantennas 138 configured and coordinated to deliver energy waves that areadditive at the target tissue dense region but subtractive at otherregions.

As mentioned with respect to many of the embodiments discussed above, itmay be desirable to create the skin fold with the assistance of suction.For example, a suction-vacuum 147 cavity can be incorporated into any ofthe aforementioned devices. FIGS. 16A-B show perspective views of oneembodiment of a suction system 147 comprising a housing 156, a suctionchamber 157, a vacuum port (not shown) for connection to a vacuum source(not shown) and twin slot microwave antennas 138 operably connected to apower source via coaxial cables 133. Also shown are cooling flow inlet134 and outlet 135 ports for each antenna 138. The vacuum source can beconfigured for providing sufficient vacuum force to grasp and hold theskin in a folded orientation within the tissue chamber 157. The devicemay utilize the suction 147 for simply grasping the skin at thebeginning of the procedure or holding the skin in place for some or allof the treatment. This area of lower pressure or suction within thedevice will help adhere the device to the skin so as to bring the targettissue into closer apposition to the antenna 138 and reduce blood flowin the target tissue, thereby enabling more efficient heating of thetissue.

The use of suction has a number of additional benefits. For example,suction can be useful in orienting the skin in the desired geometry. Asshown in the treatment configurations disclosed above, suction can helpgrasp and retain the skin in either the folded skin or elevatedconfigurations. Also, by using suction to bring the skin in position fortreatment, treatment variability can be minimized. Clinicians will nothave to worry about maintaining consistent contact force since that willbe regulated by the suction.

Furthermore, suctioning may allow for advantageous temporary occlusionof blood vessels superficial to or in the same plane as the targettissue, in embodiments where blood vessels are not preferentiallytargeted. By restricting flow through the vessels, the water content ofthe vessels would thus be decreased and prevent undesirable coagulationvia microwave energy. This can also provide a heat-sink effect asmicrowave energy would be more efficiently directed to the target tissuerather than be directed to the non-target blood vessels.

However, in some embodiments it may be desirable to employ suction suchthat blood remains in the vessel such that the vessel preferentiallyabsorbs microwave energy, such as, for example, to treat telangiectasiasor varicose veins.

Additionally, suction may help to control pain by triggering stretch andpressure receptors in the skin, thereby blocking pain signals via thegate control theory of pain management. The gate control theory holdsthat an overabundance of nerve signals arriving at the dorsal rootganglion of the spinal cord will overwhelm the system, and mask or blockthe transmission of pain receptor signals to the brain. This mechanismof pain management is exploited by implantable electrical pain controlunits, TENS systems, the Optilase system and others.

In some embodiments, a suction system 147 includes a vacuum pumpconfigured with sufficient pressure for the area of tissue acquisitiondesired. The pressure can be between about 450-700 mm Hg, and about 650mm Hg in some embodiments. The geometry of the area covered by thechamber can be ovoid in some embodiments, or any other desired shape. Inan embodiment with a 15 cm×25 cm rectangular waveguide 145 and coolingplate 115, the suction chamber 157 may have a 15 cm×25 cm centralrectangular area with two lateral 7.5 cm radius arc regions. In someembodiments, the chamber depth is less than about 30 mm, 25 mm, 20 mm,15 mm, 10 mm, 7.5 mm, 5 mm, or less. The chamber walls may, in someembodiments, be angled out from the base of the chamber 157, e.g.,between about 5-30 degrees, such as about 20 degrees.

The depth of the suction chamber 157 controls the amount that the skinis elevated when acquired and treated, which, in turn, impacts thelesion formed within the skin tissue. When treated in its compressed andelevated state, a subdermal lesion is created in the compressed tissue.When the suction 147 is released and the skin is disengaged from thechamber 157 and its compressed state, the lesion is stretched out. Theresult is a thinner and wider subdermal lesion.

The suction system 147 also can include one or more suction ports, e.g.,two ports, each connected via a suction channel to a suction zone. Thesuction zone defines a pattern to maximize suction area, which in turnmaximizes suction force. The suction area also prevents tissuedistortion. In embodiments, with a plurality of suction ports, the portsmay be connected by a suction conduit that can split into distalbranches to mate with each suction port.

The system 147 may also include a control element, such as a CPU, tocontrol various parameters as noted above. In some embodiments, thepreferred treatment sequence is (1) suction to acquire the desiredtissue; (2) pre-cool the desired tissue; (3) deliver energy to thetissue; (4) post-cool the tissue; and (5) release the suction. Othertissue acquisition systems, devices, and methods that can be used withembodiments described herein are disclosed, for example, at pp. 69-71 ofU.S. Provisional Application No. 61/045,937, previously incorporated byreference in its entirety.

The following Table 1 is a non-limiting listing of various parametersthat can be altered to control the thickness of the lesion created bythe delivered energy, as well as the depth of the protection zonecreated by the cooling system. Ranges listed are for certain embodimentsonly; other ranges or values outside the listed ranges are also withinthe scope of the invention.

TABLE 1 Effect of Varying Certain Parameters Parameter Protection ZoneDepth Lesion Size Range ↑ Power Decrease Increase 20-100 W, 40-70 W ↑Frequency Decrease Decrease 2.4 GHz-9.2 GHz, 2.45 GHz, 5.8 GHz ↑ CoolantTemp Decrease Increase −5-40 C., 10-25 C., 10 C., 22 C. (hotter) ↑Coolant flow rate Increase Decrease 100-1500 ml/min, 300- 600 ml/min,600 mL/min ↑ Depth of suction Decrease Decrease 1-20 mm, 7.5 mm chamber↑ Duration of Decrease Increase 0.1 sec-60 secs; 2-5 secs Energydelivery ↑ Duration of pre-cooling Increase Decrease 0-60 s, 0-5 s ↑Duration of post-cooling Increase Decrease 0-60 s, 0-20 s

In some embodiments, the system also includes one or more temperaturesensors. The sensors may be a thermocouple (TC), a thermistor, or afiber optic sensor (which advantageously will not interact withmicrowave energy if lacking metal). In some embodiments, the temperaturesensor is a thermocouple sensor located at the interface between theskin surface and the cooling plate. Some embodiments may also optionallyinclude a thermocouple sensor to measure the temperature of the coolantinflow and/or outflow reservoirs. The system may also include a feedbackloop configured to adjust the energy delivered and/or coolanttemperature, or alternatively shut off the system, for example, if apreset maximum skin or coolant temperature is identified. Other sensorssuch as pressure or distance sensors can be present to confirm skincontact and engagement.

Medications

In many of the treatments disclosed herein, the target tissue 105 isdamaged to yield a treatment effect. However, non-target tissue 103, 104may also be affected in some of these treatments. Such treatments mayhave complications such as pain, inflammation, infection, and scarring,which may occur both during and after treatment. Therefore, it may bebeneficial to provide the patient with medications prior to, duringand/or after the treatment to minimize the incidence and impact of thesecomplications. The medications, which could be anesthetics for pain,such as lidocaine, ropivacaine, bupivacaine, tetracaine, and procaine;steroids or nonsteroidal agents for inflammation and antibiotics forinfection, can be administered orally, topically, intravenously, or vialocal injection.

Controlled Delivery of Energy

With some of the treatments disclosed herein for delivering energy totarget tissue 105, controlled delivery of energy may be helpful inavoiding unnecessary damage to target tissue 105 (e.g., desiccation,charring, etc.) and non-target tissue 103, 104 as a result ofoverheating. A controlled delivery of energy may also result in a moreconsistent, predictable and efficient overall treatment. Accordingly, itmay be beneficial to incorporate into the energy delivery system acontroller having programmed instructions for delivering energy totissue. Additionally, these programmed instructions may comprise analgorithm for automating the controlled delivery of energy.

In an embodiment employing the controlled delivery of energy, theaforementioned controller can be incorporated into or coupled to a powergenerator, wherein the controller commands the power generator inaccordance with a preset algorithm comprising temperature and/or powerprofiles. These profiles may define parameters that can be used in orderto achieve the desired treatment effect in the target tissue. Theseparameters may include, but are not limited to, power and timeincrements, maximum allowable temperature, and ramp rate (i.e., the rateof temperature/power increase). Feedback signals comprising real-time ordelayed physiological and diagnostic measurements can be used tomodulate these parameters and the overall delivery of energy. Among themeasurements that can be taken, temperature, impedance and/or reflectedpower at the treatment site and/or target tissue 105 can be particularlyuseful. These measurements may help monitor the effect that the energydelivery has at the treatment site and at the target tissue over thecourse of the treatment. The energy controller may have fixedcoefficients or the controller coefficients may be varied depending uponthe sensed tissue response to energy delivery. Additionally, analgorithm comprising a safety profile may be employed to limit energydelivery or to limit sensed tissue temperature. These algorithms couldshut off energy delivery or modulate the energy delivery. Additionally,in treatments where thermal protection is employed, such as an activecooling element 115, the protective cooling can be modulated based onthe monitored data.

By considering temperature measurements in the delivery of energy,treatment can be administered to achieve the necessary treatment effectwhile avoiding unnecessary complications of the treatment. For example,energy delivery to target tissue 105 can be steadily increased (i.e.,ramped up) until the desired threshold temperature is reached for thetarget tissue, wherein the threshold temperature is that which isnecessary to yield a treatment effect. By ceasing the power increase, orthe delivery of energy altogether, once the threshold temperature isreached, harm to non-target tissue 103,104 resulting from additional andexcessive heating can be avoided. In some embodiments, the temperatureof the target tissue can be indirectly and noninvasively monitored bydetermining the temperature of a superficial non-target tissue 103,e.g., at the surface of the skin, and extrapolating from thattemperature measurement the target tissue temperature. Adjustments canbe made for the skin thickness of a particular patient. In someembodiments, it is desirable to maintain the superficial non-targettissue 103 temperature at less than about 45° C.

Temperature can be measured using any number of sensors, includingthermocouples and thermistors, wherein such sensors can be incorporatedinto the energy delivery element 154, the energy delivery device and/orthe energy delivery system. For example, a thermocouple can be imbeddedin the energy applicator, positioned adjacent to the antenna as part ofthe energy delivery device or located separate from the device such thatthe thermocouple is wired directly to the generator. The temperaturemeasured can be that of the tissue immediately adjacent the device, thetarget tissue or any other tissue that may provide useful temperaturemeasurements. In cases where the energy delivery element is in thermalcommunication with the surrounding tissue (e.g., via conduction), asensor that is incorporated into the energy delivery element may measurethe temperature of the element itself.

Impedance can be measured by observing a tissue's response to electricalstimulation. This measurement is useful because it can help assess theextent of energy delivery to and through tissue. For example, energythat is directed to tissue having high impedance may have difficultyinfiltrating deeper regions of tissue. This is particularly important inthe case of skin tissue, as the impedance of skin can change over thecourse of treatment. As tissue is heated, it loses moisture and itsconductivity drops and impedance increases. If the tissue is heateduntil it is desiccated, the resistivity of the tissue may impair energydelivery to surrounding tissue via electrical conduction. Employingimpedance measurement feedback in the energy delivery system canoptimize the delivery of energy to target tissue 105 while avoidingadverse consequences to both the target 105 and non-target tissue 103,104.

Staged Treatment

In many of the treatments disclosed in this specification, it may bedesirable to perform the treatment in stages. Additionally, thetreatment can be patterned such that sections of target tissue 105 aretreated in the initial stage while other sections are treated insubsequent stages. For example, as illustrated in FIG. 17, a patientcould have the regions marked “A” treated in a first stage and theregions marked “B” treated in a second stage. Additionally, thetreatment could be broken down into further stages such as at least 3,4, 5, 6, or more stages and additional regions. Optionally, treatmentcould be administered to the same regions in multiple stages such thateach region receives treatment multiple times. In one embodiment, insubsequent stages the treatment to a particular region may vary, such aswith an increased or decreased amount of energy, or with a differenttreatment type.

This approach has numerous potential benefits. First, a staged treatmentgives the body the opportunity to heal between treatments. This isparticularly important since treating or thermally damaging discreteregions of tissue over several sessions may have fewer and less severecomplications compared to treating or thermally damaging a relativelylarge area of tissue in one session. Secondly, a patterned treatmenthaving small regions of treatment may elicit a more favorable healingresponse. Since healing time is related to the distance that fibroblastsmust migrate from surrounding tissue, smaller treatment areas may healmuch faster than larger treatment areas. FIGS. 18A-E illustrate examplesof various patterned treatments.

For the medical practitioner, a staged and patterned treatment mayprovide the opportunity to track the treatment's efficacy and providefollow-up treatments tailored to the patient's specific needs. Forexample, in the case of treatments for axillary hyperhidrosis, theclinician can have follow-up sessions where sweating is mapped (e.g.,iodine staining) to (1) identify the remaining areas for treatment and(2) determine the overall reduction in sweating in the underarm area.For patients who do not necessarily desire 100% anhidrosis, a stagedtreatment may allow them to discontinue treatment at a particular point.For example, a patient suffering from a severe case of axillaryhyperhidrosis may be satisfied with at least about 20%, 30%, 40%, 50%,60%, 70%, 80%, 90% or more reduction in sweating and may only wish toparticipate in the number of treatments necessary for such reduction.

Additionally, a staged and patterned treatment can minimize the body'scontracture response during the healing process. In a process calledfibrosis (or scarring), fibroblasts lay down a mesh of collagen tofacilitate the healing of tissue. As the density of the scar increases,the treated area contracts, thereby tightening the skin within thatregion. In the case of treatments for axillary hyperhidrosis,contracture could potentially impair the patient's full range of armmotion. A treatment can be patterned and staged to minimize contractureand/or its impact on the patient. For example, the slender treatmentareas depicted in FIG. 18C would result in minimal axillary contractureand resulting impairment to range of arm motion.

A template can be used to facilitate the application of a staged and/orpatterned treatment. FIG. 19 illustrates a staged treatment seriescomprising three templates 158, 159, 160 wherein each template isconfigured to allow treatment to a different portion of the overalltreatment area. The templates 158, 159, 160 may be configured to engagean energy delivery device or one or more energy delivery elements (notshown) to facilitate the application of a staged and/or patternedtreatment. The templates 158, 159, 160 can be comprised of a singleframe made from an appropriate material such as, for example, wood,plastic or metal with removable or adjustable pieces to reflect thedesired pattern and/or stage. Alternatively, the templates 158, 159, 160may also be of one or more patterns that are drawn on the patient's skinusing a temporary marker, tattoo or dye (e.g., henna) that will remainover the course of multiple staged treatments.

System Embodiments

In some embodiments, disclosed is a system and method for usingmicrowave energy to thermally affect the sweat glands and surroundingtissue non-invasively. Such a system and method may be useful intreating, for example, excessive sweating, or hyperhidrosis. The systemincludes a microwave generator, a microwave applicator, a coolingcomponent, and a tissue acquisition component.

The microwave applicator includes one or more microwave antennas thatare placed against or adjacent the patient's skin and configured todeliver energy to a target layer at a designated depth of a patient'sskin, specifically to the region of the dermis and hypodermis wheresweat glands reside. Shielding is provided around the applicator incertain embodiments to localize the microwave energy to a targetedregion of the patient's skin.

The cooling component includes a ceramic cooling plate (such as made ofceramic) configured to contact the skin of a patient and protectivelycool a layer of skin above the target layer, e.g., the epidermis. Thecooling component also includes a coolant flow circuit chamber adjacentto the cooling plate configured to receive a cooling fluid. The coolingcomponent also includes a temperature regulating component to cool orheat the fluid and a pump to circulate the fluid.

The tissue acquisition component includes a suction chamber forelevating and receiving the skin to be treated, one or more suctionports in communication with a vacuum pump, and a thermocouple wire formeasuring the temperature of the skin.

In some embodiments, a method of reducing sweat production involvesidentifying an area of skin to be treated; activating the vacuum pump toacquire the skin within a suction chamber; cooling a first layer of theskin via a cooling element; delivering microwave energy to a secondlayer of skin containing sweat glands while the first layer of the skinis protectively cooled, the second layer deeper than the first layerrelative to the skin surface; and deactivating the vacuum pump torelease the skin.

FIG. 20 illustrates schematically a microwave applicator system 161 fortreating various skin features, according to one embodiment of theapplication. The system includes a waveguide antenna 145 operablyconnected to a coaxial cable (not shown), which is in turn connected toa microwave generator 113 (not shown).

The microwave generator 113 preferably includes a generator head, apower supply, and an isolator. The generator 113 may be configured tohave a frequency of between about 915 MHz to 15 GHz, more preferablybetween about 2.4 GHz to 9.2 GHz, such as about 2.45 GHz and 5.8 GHz,and have an output power maximum, in some embodiments, of no more thanabout 300 W, 200 W, 100 W, 75 W, or less. Various medical microwavegenerators that may be adapted for use with the disclosed embodimentsinclude, for example, those from Microsulis Medical Ltd., (9.2 GHz MEATreatment System) (Denmaed, Hants, UK); Flex 2 or Flex 4 2.45 GHz MWablation system from AFx, Inc., Fremont, Calif.; the Targis andProstatron 915 MHz Systems from Urologix, Minneapolis, Minn.); and theBSD-500 hyperthermia system from BSD Medical, Salt Lake City, Utah.

The antenna 145 preferably has a frequency of between about 915 MHz to15 GHz, more preferably between about 2.4 GHz to 9.2 GHz, such as about2.45 GHz and 5.8 GHz.

The waveguide antenna 145 preferably has a cross-sectional sizeconfigured to the desired operational frequency and field configurationof the waveguide. Generally, lowest-order Transverse Electric (TE) modesare utilized (e.g., TE₁₀), although others are possible, such asTransverse Magnetic (TM), Transverse ElectroMagnetic (TEM),effervescent, or a hybrid mode. For example, the width and height(rectangular) or diameter (circular) waveguide geometry correlate withthe operational frequency and field configuration of the waveguide 145.

The length of the waveguide 145 is preferably adjusted such that thephysical length of the waveguide 145 corresponds to an electrical lengththat is a half-wavelength multiple of the guided wavelength at thedesired operational frequency.

The waveguide 145 can have any cross-sectional geometry depending on thedesired clinical objective and geometry of the particular anatomicalarea to be treated. In some embodiments, the waveguide 145 has arectangular, circular, elliptical, or hexagonal cross-sectionalgeometry.

In some embodiments, the coaxial feed (not shown) can be placed betweenabout 1 mm to 10 mm from the (inner) back wall of the waveguide 145,with an insertion depth of 1 mm to 7 mm. The placement is mostpreferably optimized for efficient transfer of power from coaxial feedto waveguide 145.

To have the desired energy density in the region of target tissue, it ispreferred that the antenna 145 be within 0.5-5 mm of the epidermis 102(e.g., between about 1.5-2 mm, such as about 1.75 mm). This distance maybe referred to herein as the antenna standoff height 162, as shown inFIG. 22A, which shows an alternative embodiment of a slot antennaconfiguration. Variation of the standoff height 162 affects the spreadof the microwave radiation. With a very large standoff height 162, areduced energy density over a larger volume is achieved. Conversely,with little to no standoff height 162 the energy density is generallymuch higher over a smaller volume. To achieve therapeutic energy densitylevels with a large standoff height 162, significantly increased inputpower levels are necessary. The absorption pattern of the microwaveenergy at depth in tissue, strongly influenced by the standoff 162,directly influences the relative safety margin between target andnon-target (deep) tissues. Finally, standoff height 162 causes largevariation in the loading conditions for the waveguide 145, withreflected power levels observed by the antenna changing with standoffchanges.

Distal end of the waveguide 145 can be operably connected to the coolingsystem, which includes a cooling fluid circuit 163 at least partiallysuperimposed on a cooling plate 166, which preferably directly contactsthe skin 119 to be treated. Underlying fat 164 and muscle layers 165 arealso schematically shown. In one embodiment with a rectangularwaveguide, the cooling plate has a rectangular geometry and dimensionsof 15 mm×25 mm. The thickness of the flow chamber is preferably lessthan about 3 mm, 2 mm, 1.5 mm, 1 mm, 0.75 mm, or 0.5 mm.

Also illustrated in FIG. 20 are one or more vacuum ports that areoperably connected to a source of vacuum, as previously described. Theapplicator, cooling components, and vacuum ports are preferably allconnected into a self-contained housing 168 as shown.

FIG. 21 illustrates schematically the underside of the waveguideapplicator system 161 of FIG. 20. Shown is the waveguide 145, which isoperably connected distally to the cooling fluid circuit running overcooling plate 166 (rectangular area as shown), and two vacuum ports 167each lateral to the cooling plate 166. All elements are preferablycontained within housing 168 to facilitate efficient energy delivery,cooling, and suction to the specific area to be treated.

FIG. 21A illustrates a side perspective view of a microwave applicator161 including handle 169 for a waveguide antenna system, according toone embodiment of the application. FIG. 21B illustrates another view ofthe waveguide applicator handle 169 of FIG. 21A, also illustrating thehousing 168 (e.g., the suction chamber), vacuum port 167, and coolingplate 166.

Single Slot Embodiment

In some embodiments, a microwave applicator system 170 includes a slotantenna 138. The slot antenna 138 includes a proximal portion 143, abent portion 144, a slot 142, and a distal tip portion 141 as shown inFIG. 22. The diameter of the slot coaxial cable (not shown) within theslot antenna 138, is preferably large enough to handle the desiredmicrowave power, which may be no more than about 200 watts, 150 watts,100 watts or less in some embodiments. The diameter of the slot antenna138 can also be varied to introduce changes to the radiationcharacteristics of the antenna. In some embodiments, the slot 138diameter is between about 0.047″ to 0.500″, such as between about 0.085″to 0.25″ in some embodiments, or such as about 0.085″ or 0.141″ incertain embodiments.

The slot 142 width, in some embodiments, can be between about 0.5 mm to5 mm, such as between about 1 mm to 2 mm, such as about 1.5 mm in someembodiments. In general, the slot 142 width has a strong influence onboth the operational frequency as well as the “depth of resonance” (inother words, the amount of coupling into the tissue at the optimalfrequency). While the slot 142 is preferably circumferential,non-circumferential slots 142 are also within the scope of theapplication.

The distal antenna tip portion 141, which is the portion 141 distal tothe slot 142 as shown, can have a length in some embodiments of about0.5 mm-15 mm, such as between about 1 mm-10 mm, such as about 8 mm. Thelength of the tip portion 141 can influence the operational frequency ofthe antenna. For example, a longer distal tip portion 141 will result ina lower frequency.

The slot 142 width and the length of the distal antenna tip 141 portionare primary variables that affect the relative power deposition(Specific Absorption Rate) characteristics at depth in tissue, as wellas the efficiency of power transfer from the antenna into tissue at thedesired frequency.

The slot antenna 138, in some embodiments, includes a bent portion 144between the proximal slot antenna 143 and the slot 142. The bent portion144 can have any appropriate angle of curvature, such as at least about15, 30, 45, 60, 75, 90, 105, 120, 135 degrees, or more. As shown, thebent portion 144 has an angle of curvature of approximately 90 degrees.A bent portion 144 of a slot antenna 138 can have several advantages.Slot antennas 138 which are fed by an unbalanced coaxial line, have backcurrents that cause back-radiated fields to travel proximally up theouter conductor of the cable back towards the power source. The bend 144is introduced into the cable at a point before the first standing wavecaused by the back fields. This ensures there are no unwanted tissueablation areas that can occur at locations along the cable where theouter shielding of the cable is in close proximity to the tissue. Thebend 144 location also affects power transfer characteristics from theantenna into tissue and ensures greater consistency across treatments.

With respect to the antenna stand-off height 162 as previouslydescribed, to obtain a desired energy density in the region of targettissue, it is preferred that the antenna be within 0.5-5 mm of the skin(e.g., between about 1.5-2 mm, such as about 1.75 mm).

FIG. 22A illustrates various dimensional parameters of a single slotantenna 138 according to one embodiment that can be adjusted dependingon the energy delivered and the skin surface area to be treated. Shownis the antenna stand-off height 162, antenna diameter 172, coolingchamber thickness 173, and shielding/body height 174. While thevariables are illustrated with a single slot antenna configuration, itwill be appreciated that the parameters can be adjusted for otherantenna embodiments as well.

As shown in the schematic drawing of FIG. 22A, a slot antenna system 170(as opposed to a waveguide antenna system), in some embodiments,includes a microwave shielding element 139 due to the omnidirectionalnature of energy delivery of the slot antenna 138. Shielding elements139 can be advantageous for one or more of the following reasons: (1)shielding may increase efficiency and therefore increase overall power;(2) by preventing parts of the field from straying, the shielding mayallow for greater consistency and reliability across multipletreatments; (3) shielding may choke off proximally traveling currentsdown the outer conductor, thereby eliminating the back-radiated fields;(4) shielding may remove the inherently omnidirectional radiationcharacteristic of the antenna, redirecting the energy back towards thetarget tissue; and (5) the geometry of the shielding may be used as anadditional tool to achieve an optimal power deposition characteristic intissue, as well as allow for efficient power transfer.

The shielding 139 may be solid or mesh in some embodiments, and may haveabsorptive and/or reflective shielding properties. For example, graphitecan be used if absorptive shielding is desired. Metal shieldings aregenerally reflective without being absorptive. If reflective meshshielding is used, the pore size used is generally related to thewavelength (i.e., larger wavelength allows for larger openings). Meshshielding advantageously allows for visualization of tissue acquisitionand, accordingly, confirmation of tissue engagement by the operator.

The shielding 139 is preferably located at an optimal distance away fromthe slot antenna 138. When the shielding 139 is too close to the slotantenna 138, the antenna field may couple to part of the shielding 139(usually an edge) and the coupled portion will begin to radiate atunwanted locations, creating what is known as a “hot spot” effect.Therefore, in some embodiments, the lateral shielding 139 is kept at adistance, such as at least about 5 mm, 7 mm, 10 mm, or more, away fromthe antenna 138 so as to sufficiently limit or ideally, eliminate thehot spot effect. Additionally, if some coupling exists at the shieldedge, the shielding may be lifted such that it is not in direct contactwith the skin, thus reducing or removing any tissue absorption in thislocation. The proximal back wall of shielding is preferably kept at anappropriate distance from the coaxial cable so as to prevent backradiation of the field and further focus the field toward a targetwavelength. The shielding may extend adjacent to and parallel with theskin surface to protect the skin. As it may be advantageous to haveshielding spaced laterally at least a certain distance from the antenna,shielding portions of the skin surface may be desirable in order tocreate a treatment window of defined width. The geometry of theshielding element can be determined depending on the geometry of thetreatment area and the desired clinical result. Some examples ofshielding element geometries are, for example, cylindrical,hemispherical, and rectangular.

The cooling components, such as cooling fluid (not shown) and plate 115,as well as tissue acquisition components and their respective parametersmay be as previously described. The control system may also be aspreviously described, however, operation parameters can be variedwithout undue experimentation in order to achieve a result similar tothat of the waveguide embodiments.

FIG. 23 illustrates schematically the underside of the slot applicatorsystem 170 of FIG. 22. Shown is the slot antenna 138, which is operablyconnected distally to the cooling fluid circuit running over coolingplate 115, and two vacuum ports 167 each lateral to the cooling plate115. Shielding 139 preferably surrounds at least a part of the housing171 to prevent unwanted energy delivery outside the desired treatmentarea.

Twin Slot

In some embodiments, the microwave applicator system 175 includes aplurality of slot antennas 176, as illustrated schematically in FIG. 24above. In such configurations, two or more coaxial slot antennas 176operate as a phased array. The spacing of antennas 176, the alignment oftissue pinch 177 with the antennas 176, and the phase relationshipbetween the inputs to the two antennas 176 may be additional variablesthat can be altered by one skilled in the art depending on the desiredclinical result.

The interaction between the e-fields created by each antenna 176 mayvary depending on the spacing of the antennas 176 with respect to eachother. Care must be taken not to space the antennas 176 too closelytogether, which can lead to large power coupling from one antenna intothe other that travels back into the microwave generator (not shown).Antennas 176 can be spaced from 0 mm to 10 mm away from the coolingfluid in a “side of the pinch” configuration, and can be spaced at adistance of approximately 8 mm to 30 mm apart from each other in an“above the pinch” configuration.

The relative alignment of tissue pinch acquisition with antennas 176 canalso be altered depending on the desired clinical result. Twoconfigurations have been shown to lead to advantageous power depositionpatterns in tissue—either alignment of the twin antennas 176 on eitherside of the “pinch” 177 as shown or in other embodiments, alignment ofthe twin antennas 176 above the “pinch” 177. In both cases the antennapinch 177 alignment can be adjusted such that areas of high e-field canbe focused in the treatment site while reducing fields in the non-targettissue.

The antennas 176 can be configured for phased operation. Driving theantennas 176 in-phase results in a focused e-field pattern, withconstructive interference between the two antennas 176 occurring in thetarget region and destructive interference occurring in the non-targetregion. Such focusing, in combination with the geometry of the tissuepinch 177 configuration, leads to a higher potential for lower-frequencydrive signals to be utilized than in a single-antenna system aspreviously described.

In some embodiments, in addition to in-phase operation, the relativespatial position of the peak e-field region between the two antennas 176can be varied by introducing a phase difference between the inputsignals to the antennas 176 depending on the desired clinical result.This allows the treatment region to be directed to different locationswith great accuracy by a process known as “beam steering.” For example,the treatment region can be re-directed from a region laying exactlyin-between the two antennas 176 (with in-phase operation), to abifurcated treatment region that has dual treatment areas in the tissueregions that lay in closest proximity to each antenna (with anti-phaseoperation). FIG. 24A illustrates a simulation of the two antennas withan in-phase drive operation.

FIG. 24B illustrates a simulation of the two antennas in anti-phasedrive (103 degree phase shift between drive signals of the first antennaand the second antenna).

FIG. 24C illustrates a simulation of the two antennas with a 170 degreephase shift between drive signals of the first antenna and the secondantenna.

FIG. 24D illustrates a simulation of the two antennas with a 155 degreephase shift between drive signals of the first antenna and the secondantenna.

In the dual slot embodiments, shielding 1208 is preferably present tominimize energy distribution outside of the treatment area and can be aspreviously described.

The cooling components and parameters of a multi-slot antenna system 175can be similar to those described with respect to the waveguideembodiments, however there are some geometric changes. In oneexemplifying embodiment, with the dual-slot antenna configuration 175shown, the cooling chamber has five distinct cooling faces (178 a, 178b, 178 c, 178 d, 178 e), or surfaces: one surface 178 c at the top ofthe tissue pinch 177 (measuring about 9 mm×27 mm of cooling platesurface); two surfaces 178 b, 178 d at the sides of the pinch extendinggenerally vertically (measuring about 10 mm×27 mm of cooling platesurface each); and two lateral surfaces 178 a, 178 e at the bottom ofthe pinch 177 extending generally horizontally (measuring about 10 mm×27mm of cooling plate surface each). In some embodiments, the coolingchamber optionally includes a thin polyamide sheet which is used toconnect the ceramic cooling plates 178 a-e.

The tissue acquisition components (not shown), e.g., suction components,may be similar to those previously described, with the followingadditional considerations. By pinching the skin, the dermis and thehypodermis layers may, in essence, be isolated from the muscle layer.This enables the device to deliver a very controlled amount of energy tothe dermis while protecting the muscle layer. The vacuum pump may have asuction pressure, in some embodiments, of about 400-700 mmHg, such asabout 650 mmHg. The suction chamber may have any desired geometry. Forexample, in one embodiment, the suction chamber may have a centralrectangular portion of about 10 mm in height×40 mm in length and athickness of 9 mm. The material of the suction chamber housing ispreferably transparent or translucent to enable visual confirmation ofskin engagement.

The control system may also be as previously described, however,operation parameters can be varied without undue experimentation inorder to achieve a result similar to that of the waveguide embodiments.

FIG. 25 above illustrates schematically the underside of the dual slotapplicator system 175 of FIG. 24. Shown are dual slot antennas 176,which are operably connected distally to the cooling fluid circuitrunning over cooling plate 178, and two vacuum ports 182 each lateral tothe cooling plate 178. Shielding 181 preferably is present around atleast a part of the housing 179 to prevent unwanted energy deliveryoutside the desired treatment area.

FIG. 26 below illustrates one example of a microwave treatment system,including a computer 183 for data collection, a microwave signalgenerator and amplifier 184, a vacuum pump 185 for tissue acquisition, atemperature control unit (which may be a chiller in some embodiments)and circulating pump 188.

FIG. 27A below is a histologic cross-section of a normal porcineapocrine gland 186 (circled) that is in the dermal/hypodermal interface.

FIG. 27B below is a histologic cross-section of a porcine sweat gland187 (circled) one week status-post microwave therapy, illustrating glanddisorganization and leukocytic infiltration related to thepost-treatment inflammatory response. This histology demonstrates theselective nature of the microwave application. This type of result canbe achieved with several different carefully selected combinations ofantenna design and energy/cooling algorithms. One such combination is a5.8 GHz waveguide antenna used at 55-60 W, with 3 seconds of energyapplication and a cooling of 22° C. for both during and 20 sec afterenergy application. This combination has been shown to provide positiveresults for both animals and humans.

Overview of Certain Methods, Systems and Other Embodiments

In one embodiment, the present application provides a method fortreating a skin tissue of a patient comprising positioning a microwaveenergy delivery applicator over the skin tissue, securing the skintissue proximate to the microwave energy delivery applicator, coolingthe surface of the skin tissue; and delivering energy via the microwaveenergy delivery applicator to the skin tissue sufficient to create athermal effect in a target tissue within the skin tissue.

In some embodiments, positioning a microwave energy delivery applicatorover the skin tissue may further comprise positioning over the skintissue a microwave antenna selected from the group consisting of singleslot, multiple slot, waveguide, horn, printed slot, helical, patch,Vivaldi and combinations thereof.

In some embodiments, securing the skin tissue proximate to the microwaveenergy delivery applicator may further comprise applying suction to theskin tissue. In one embodiment, applying suction to the skin tissue mayfurther comprise at least partially acquiring the skin tissue within asuction chamber adjacent to the energy delivery applicator.

In some embodiments, securing the skin tissue may further compriseelevating the skin tissue.

In some embodiments, cooling the surface of the skin tissue may furthercomprise positioning a cooling element in contact with the skin surface.

In some embodiments, cooling the surface of the skin tissue may furthercomprise conductively cooling the skin surface.

In some embodiments, cooling the surface of the skin tissue may furthercomprise convectively cooling the skin surface.

In some embodiments, cooling the surface of the skin tissue may furthercomprise conductively and convectively cooling the skin surface.

In some embodiments, the target tissue within the skin tissue may beselected from the group consisting of collagen, hair follicles,cellulite, eccrine glands, apocrine glands, sebaceous glands, spiderveins and combinations thereof.

In some embodiments, the target tissue within the skin tissue maycomprise the interface between the dermal layer and subcutaneous layerof the skin tissue.

In some embodiments, the thermal effect in the target tissue maycomprise thermal alteration of at least one sweat gland.

In some embodiments, the thermal effect in the target tissue comprisesablation of at least one sweat gland.

In one embodiment, the method may further comprise monitoring adiagnostic parameter of the skin tissue. The diagnostic parameter may beselected from the group consisting of impedance, temperature, andreflected power.

In one embodiment, the method may further comprise administering to thepatient a medication selected from the group consisting of anesthetics,steroids, and antibiotics. Administering medication to the patient mayfurther comprise administering the medication orally, topically or viainjection.

In one embodiment, the present application provides a system related totreating a skin tissue of a patient comprising a microwave energygenerator; a microwave antenna configured for placement proximate to theskin tissue of the patient; a cooling element configured for placementin contact with the skin tissue of the patient; and a suction elementconfigured for elevating the skin tissue and placing the skin tissue incontact with the cooling element; wherein the microwave antenna isoperatively coupled to the microwave energy generator, and wherein themicrowave antenna is configured to deliver energy to the skin tissuesufficient to create a thermal effect in a target tissue within the skintissue.

In some embodiments, the microwave antenna may be selected from thegroup consisting of single slot, multiple slot, waveguide, horn, printedslot, patch, Vivaldi and combinations thereof.

In some embodiments, the microwave antenna may be a waveguide antenna.In one embodiment, the waveguide antenna may comprise an array ofwaveguide antennas.

In some embodiments, the microwave antenna may be a single slot antenna.

In some embodiments, the microwave antenna may be a dual slot antenna.

In some embodiments, the microwave energy generator may be configured todeliver microwave energy at a frequency of about 2.45 GHz.

In some embodiments, the microwave energy generator may be configured todeliver microwave energy at a frequency of about 5.8 GHz.

In some embodiments, the cooling element may be selected from the groupconsisting of a solid coolant, liquid spray, gaseous spray, coolingplate, thermo-electric cooler and combinations thereof.

In some embodiments, the cooling element may comprise athermally-conductive plate. The thermally-conductive plate may besubstantially transparent to microwave energy. In one embodiment, thecooling element may further comprise a flow chamber adjacent to thethermally-conductive plate, wherein the flow chamber is configured toretain a liquid coolant. In one embodiment, the liquid coolant may beconfigured to flow through the flow chamber, thereby cooling thethermally-conductive plate. The liquid coolant may be selected from thegroup consisting of water, deionized water, alcohol, oil andcombinations thereof. In one embodiment, the liquid coolant may comprisedeionized water. In one embodiment, the liquid coolant may comprisedeionized water and alcohol.

In some embodiments, the thermally-conductive plate may comprise aceramic.

In some embodiments, the suction element may comprise a suction chamberconfigured to acquire at lease a portion of the skin tissue. The suctionelement may be operatively coupled to a vacuum source. In oneembodiment, the suction chamber may be further configured with at leastone tapered wall.

In one embodiment, the system further comprises a temperature sensor.The temperature sensor may comprise a thermocouple configured formonitoring the temperature of the skin tissue.

In one embodiment, the present application provides a microwave energydelivery apparatus related to non-invasively treating a skin tissue of apatient comprising a thermally-conductive plate adjacent to themicrowave antenna; and a suction chamber; wherein thethermally-conductive plate is configured to contact the skin tissue,cool the skin tissue and physically separate the skin tissue from themicrowave antenna, and wherein the suction chamber is configured to atleast partially acquire the skin tissue and bring the skin tissue incontact with the cooling plate.

In one embodiment, the microwave energy delivery apparatus may furthercomprise a shield configured for containing excess energy fields. In oneembodiment, the shield may be comprised of a reflective material. In oneembodiment, the shield may be comprised of an energy absorbent material.

In one embodiment, the present application provides a method related tocreating a subdermal lesion in a skin tissue of a patient comprisingdelivering microwave energy to the skin tissue and applying a coolingelement to the skin tissue, wherein the microwave energy is delivered ata power, frequency and duration and the cooling element is applied at atemperature and a duration sufficient to create a lesion at theinterface between the dermis layer and subcutaneous layer in the skintissue while minimizing thermal alteration to non-target tissue in theepidermis and dermis layers of the skin tissue.

In one embodiment, the present application provides a method related toreducing sweat production in a patient comprising identifying an area ofskin to be treated, activating a vacuum pump to acquire the skin withina suction chamber, cooling a first layer of the skin via a coolingelement, delivering microwave energy to a second layer of skincontaining sweat glands sufficient to thermally alter the sweat glandswhile the first layer of skin is protectively cooled, the second layerdeeper than the first layer relative to the skin surface anddeactivating the vacuum pump to release the skin.

Unless the context clearly requires otherwise, throughout thedescription and the claims, the words “comprise,” “comprising,” and thelike are to be construed in an inclusive sense as opposed to anexclusive or exhaustive sense; that is to say, in a sense of “including,but not limited to.” Words using the singular or plural number alsoinclude the plural or singular number respectively. When the claims usethe word “or” in reference to a list of two or more items, that wordcovers all of the following interpretations of the word: any of theitems in the list, all of the items in the list, and any combination ofthe items in the list.

The above detailed descriptions of embodiments of the invention are notintended to be exhaustive or to limit the invention to the precise formdisclosed above. Although specific embodiments of, and examples for, theinvention are described above for illustrative purposes, variousequivalent modifications are possible within the scope of the invention,as those skilled in the relevant art will recognize. For example, whilesteps are presented in a given order, alternative embodiments mayperform steps in a different order. The various embodiments describedherein can also be combined to provide further embodiments.

Related methods, apparatuses and systems utilizing microwave and othertypes of therapy, including other forms of electromagnetic radiation,and further details on treatments that may be made with such therapies,are described in the above-referenced provisional applications to whichthis application claims priority, the entireties of each of which arehereby incorporated by reference: U.S. Provisional Patent ApplicationNo. 60/912,889, entitled “Methods and Apparatus for Reducing SweatProduction,” filed Apr. 19, 2007, U.S. Provisional Patent ApplicationNo. 61/013,274, entitled “Methods, Delivery and Systems for Non-InvasiveDelivery of Microwave Therapy,” filed Dec. 12, 2007, and U.S.Provisional Patent Application No. 61/045,937, entitled “Systems andMethods for Creating an Effect Using Microwave Energy in SpecifiedTissue,” filed Apr. 17, 2008. While the above-listed applications mayhave been incorporated by reference for particular subject matter asdescribed earlier in this application, Applicant intends the entiredisclosures of the above-identified applications to be incorporated byreference into the present application, in that any and all of thedisclosures in these incorporated by reference applications may becombined and incorporated with the embodiments described in the presentapplication. Specific non-limiting examples of embodiments that may beutilized with systems, apparatuses and methods described herein includeembodiments seen for example, in FIGS. 2-25 and pp. 9-18 and 56-69 ofApplication No. 61/045,937, previously incorporated by reference in itsentirety.

In general, the terms used in the following claims should not beconstrued to limit the invention to the specific embodiments disclosedin the specification, unless the above detailed description explicitlydefines such terms. While certain aspects of the invention are presentedbelow in certain claim forms, the inventors contemplate the variousaspects of the invention in any number of claim forms. Accordingly, theinventors reserve the right to add additional claims after filing theapplication to pursue such additional claim forms for other aspects ofthe invention.

What is claimed is:
 1. A system for treating a skin tissue of a patientcomprising: a microwave energy generator, the microwave energy generatorbeing configured to deliver microwave energy at a first frequency; anarray of waveguide antennas configured for placement proximate to theskin tissue, the array of waveguide antennas being configured forsimultaneous or sequential treatment of multiple sections of skin tissueand being configured to radiate electromagnetic radiation; a coolingplate configured for placement in contact with the skin tissue; acooling fluid circuit at least partially superimposed on the coolingplate and configured to retain a liquid coolant between the coolingplate and the array of microwave antennas; a suction element configuredfor elevating the skin tissue and placing the skin tissue in contactwith the cooling plate; wherein the array of microwave antennas areoperatively coupled to the microwave energy generator, and wherein thearray of microwave antennas are configured to deliver energy to the skintissue sufficient to create a thermal effect in a target tissue withinthe skin tissue.
 2. The system of claim 1, wherein the cooling platecomprises a thermally-conductive cooling plate.
 3. The system of claim2, wherein the thermally-conductive cooling plate is substantiallytransparent to microwave energy.
 4. The system of claim 1, wherein thecooling plate is configured to cool the skin tissue and physicallyseparate the skin tissue from the array of microwave antennas.
 5. Thesystem of claim 2, wherein the thermally-conductive cooling platecomprises a ceramic plate.
 6. The system of claim 1, wherein the liquidcoolant is selected from the group consisting of water, deionized water,alcohol, and oil.
 7. The system of claim 1, wherein the suction elementcomprises a suction chamber configured for elevating target tissuecomprising a portion of the skin tissue from underlying tissue.
 8. Thesystem of claim 1, further comprising a temperature sensor comprising athermocouple configured for monitoring the temperature of the skintissue.
 9. The system of claim 1, wherein the first frequency is about5.8 GHz.
 10. A method for treating a skin tissue of a patientcomprising: providing a microwave energy generator to deliver microwaveenergy at a first frequency; placing an array of waveguide antennasoperatively coupled to the microwave energy generator proximate to theskin tissue for performing simultaneous or sequential treatment ofmultiple sections of skin tissue and for radiating electromagneticradiation; placing a cooling plate in contact with the skin tissue, thecooling plate having a cooling fluid circuit at least partiallysuperimposed on the cooling plate; using the cooling fluid circuit toretain a liquid coolant between the cooling plate and the array ofmicrowave antennas; using a suction element to elevate the skin tissueand placing the skin tissue in contact with the cooling plate; anddelivering energy to the skin tissue via the array of microwave antennassufficient to create a thermal effect in a target tissue within the skintissue.
 11. The method of claim 10, wherein the microwave energygenerator delivers microwave energy at a frequency of about 5.8 GHz. 12.The method of claim 10, wherein the cooling plate cools the skin tissueand physically separates the skin tissue from the array of microwaveantennas.
 13. The method of claim 10, wherein the suction elementcomprises a suction chamber, the method further comprising using thesuction chamber to elevate target tissue comprising a portion of theskin tissue from underlying tissue.
 14. The method of claim 10, furthercomprising providing a temperature sensor having a thermocouple, whereinthe thermocouple monitors the temperature of the skin tissue.